The August 20 edition of The Economist includes an
article (restricted to Economist subscribers as of this writing) makes
an interesting claim:
But "spam", unsolicited e-mail, seems to be in retreat. The
amount of spam that swishes through the internet is holding steady
or declining, according to most studies. And of the stuff that
still exists, the vast majority is blocked by filters before it
gets to an inbox.
The core of the article is based on a
MessageLabs report stating that spam, which constituted 83% of all
email traffic in January, fell to "only" 67% in June. 67% remains a
horrifying number, but it also clearly is a step in the right direction.
Interestingly, your editor's personal spam indicator, currently running at
about 4,000/day, does not show any decline at all. Some people, it seems,
are just lucky.
The Economist credits a number of factors in the decline. Filters are one
of those, though the article only mentions proprietary offerings. (Said
proprietary filters are credited with 95% effectiveness, incidentally; your
editor can attest that a well-trained SpamAssassin can do much better than
that). Smarter recipients are another; evidently most Internet users have
already enlarged whatever parts of their anatomy they felt were too small,
or figured out that it wasn't going to happen for them. High-profile legal
setbacks for selected spammers have provided a small disincentive. And
phishing attacks, which are very much on the increase, have convinced many
users that spam can be dangerous and is best avoided.
Phishing is where the action is now - especially in South
America, it would seem, where a strong interest in postcard sites makes
attacks relatively easy. Since there is money in phishing, this problem is
likely to grow, at least until enough people get burned that a general
awareness sets in. It is a somewhat ironic outcome, meanwhile, that the
phishers may be helping to take the profits out of spam, and thus reducing
the problem.
Declaring victory on spam seems somewhat premature, however. The costs of
carrying that much garbage through the email system, filtering, and
shoveling out mailboxes remain high. But wouldn't it be interesting if the
arms race between spammers and their opponents turned out to be winnable -
by the good guys - after all?
Insecure temporary file usage was found in the cvsbug program. It is possible that a malicious user could use this to execute arbitrary
instructions as the user running cvsbug.
A buffer overflow flaw in Elm was
discovered that was triggered by viewing a mailbox containing a message
with a carefully crafted 'Expires' header. An attacker could create a
malicious message that would execute arbitrary code with the privileges of
the user who received it.
David Howells discovered a local Denial of Service vulnerability in
the key session joining function. Under certain user-triggerable
conditions, a semaphore was not released properly, which caused
processes which also attempted to join a key session to hang forever.
(CAN-2005-2098)
David Howells discovered a local Denial of Service vulnerability in
the keyring allocator. A local attacker could exploit this to crash
the kernel by attempting to add a specially crafted invalid keyring.
(CAN-2005-2099)
Balazs Scheidler discovered a local Denial of Service vulnerability in
the xfrm_compile_policy() function. By calling setsockopt() with an
invalid xfrm_user policy message, a local attacker could cause the
kernel to write to an array beyond its boundaries, thus causing a
kernel crash. (CAN-2005-2456)
Tim Yamin discovered that the driver for compressed ISO file systems
did not sufficiently validate the input data. By tricking an user into
mounting a malicious CD-ROM with a specially crafted compressed ISO
file system, he could cause a kernel crash. (CAN-2005-2457)
It was discovered that the kernel's embedded zlib compression library
was still vulnerable to two old vulnerabilities of the standalone zlib
library. This library is used by various drivers and can also be used
by third party modules, so the impact varies. (CAN-2005-2458,
CAN-2005-2459)
Peter Sandstrom discovered a remote Denial of Service vulnerability in
the SNMP handler. Certain UDP packages lead to a function call with
the wrong argument, which resulted in a crash of the network stack.
(CAN-2005-2548)
Herbert Xu discovered that the setsockopt() function was not
restricted to privileged users. This allowed a local attacker to
bypass intended IPSec policies, set invalid policies to exploit flaws
like CAN-2005-2456, or cause a Denial of Service by adding policies
until kernel memory is exhausted. Now the call is restricted to
processes with the CAP_NET_ADMIN capability. (CAN-2005-2555)
Kismet is vulnerable to a heap overflow when handling pcap captures and
to an integer underflow in the CDP protocol dissector. With a specially
crafted packet an attacker could cause Kismet to execute arbitrary code
with the rights of the user running the program.
Javier Fernández-Sanguino Peña noticed that the pwmconfig script created
temporary files in an insecure manner. This could allow a symlink attack to
create or overwrite arbitrary files with full root privileges since
pwmconfig is usually executed by root.
Two security related problems have been discovered in Mantis, a
web-based bug tracking system. A remote attacker could insert arbitrary
SQL code into SQL statements and a remote attacker was able to insert
arbitrary HTML code bug reports, hence, cross site scripting.
A number of vulnerabilities were discovered in OpenVPN that were fixed in
the 2.0.1 release:
A DoS attack against the server when run with "verb 0" and without
"tls-auth" when a client connection to the server fails certificate
verification, the OpenSSL error queue is not properly flushed. This could
result in another unrelated client instance on the server seeing the error
and responding to it, resulting in a disconnection of the unrelated client.
A DoS attack against the server by an authenticated client that sends a
packet which fails to decrypt on the server, the OpenSSL error queue was
not properly flushed. This could result in another unrelated client
instance on the server seeing the error and responding to it, resulting in
a disconnection of the unrelated client.
A DoS attack against the server by an authenticated client is possible in
"dev tap" ethernet bridging mode where a malicious client could
theoretically flood the server with packets appearing to come from hundreds
of thousands of different MAC addresses, resulting in the OpenVPN process
exhausting system virtual memory.
If two or more client machines tried to connect to the server at the same
time via TCP, using the same client certificate, a race condition could
crash the server if --duplicate-cn is not enabled on the server.
A buffer overflow has been discovered in the PCRE, a widely used library
that provides Perl compatible regular expressions. Specially crafted
regular expressions triggered a buffer overflow. On systems that accept
arbitrary regular expressions from untrusted users, this could be exploited
to execute arbitrary code with the privileges of the application using the
library.
A bug was discovered in the PEAR XML-RPC Server package included in PHP. If
a PHP script is used which implements an XML-RPC Server using the PEAR
XML-RPC package, then it is possible for a remote attacker to construct an
XML-RPC request which can cause PHP to execute arbitrary PHP commands as
the 'apache' user.
A bug was found in the way slocate processes very long paths. A local user
could create a carefully crafted directory structure that would prevent
updatedb from completing its file system scan, resulting in an incomplete
slocate database.
The GNU a2ps utility fails to properly sanitize filenames, which can be
abused by a malicious user to execute arbitrary commands with the
privileges of the user running the vulnerable application. More
information at Security
Focus.
A buffer overflow bug has been found in Adobe Acrobat Reader. It is
possible to execute arbitrary code on a victim's machine if the victim
opens a malicious PDF file.
A buffer overflow in the Bluetooth FTP client (BTFTP) in Nokia Affix 2.1.2
and 3.2.0 allows remote attackers to execute arbitrary code via a long
filename in an OBEX file share. Also remote attackers may execute
arbitrary commands via shell metacharacters in the filename argument of a
PUT command.
Watchfire reported a flaw that occurred when using the Apache server as an
HTTP proxy. A remote attacker could send an HTTP request with both a
"Transfer-Encoding: chunked" header and a "Content-Length" header. This
caused Apache to incorrectly handle and forward the body of the request in
a way that the receiving server processes it as a separate HTTP request.
This could allow the bypass of Web application firewall protection or lead
to cross-site scripting (XSS) attacks.
Marc Stern reported an off-by-one overflow in the mod_ssl CRL verification
callback. In order to exploit this issue the Apache server would need to
be configured to use a malicious certificate revocation list (CRL).
AWStats has a command injection vulnerability that can
be exploited by specially crafting referrer URLs that
contain Perl code. The code can then be executed with the
privileges of the web server.
The bluez-utils package (through version 2.19) fails to properly validate device names. As a result, pairing the system with a device containing a maliciously-crafted name could result in the execution of arbitrary commands as root.
A race condition in bzip2 1.0.2 and earlier allows local users to modify
permissions of arbitrary files via a hard link attack on a file while it is
being decompressed, whose permissions are changed by bzip2 after the
decompression is complete. Also specially crafted bzip2 archives may cause
an infinite loop in the decompressor.
There is a vulnerability in
cpio (2.6 and previous) that allows a malicious cpio file to
extract to an arbitrary directory of the attackers choice. cpio will
extract to the path specified in the cpio file, this path can be absolute.
The CUPS printing system has a problem with queue name
case-sensitivity matching that can cause a security policy override. An
unauthorized user can use this to gain print to a protected queue.
Cyrus-imapd, prior to version 2.2.12, contains several buffer overflows which could be exploited by an (authenticated) attacker to run code on the server system.
From the Red Hat alert: "Dan Reed discovered that a user can send and listen to messages on another
user's per-user session bus if they know the address of the socket." At current usage levels, this vulnerability is not particularly threatening.
Max Vozeler discovered a format string vulnerability in the "movemail"
utility of Emacs. By sending specially crafted packets, a malicious
POP3 server could cause a buffer overflow, which could be exploited to
execute arbitrary code with the privileges of the user and the "mail"
group.
Erik Sjölund has discovered several security relevant problems in enscript,
a program to convert ASCII text into Postscript and other formats.
Unsanitized input can cause the execution of arbitrary commands via EPSF
pipe support. Due to missing sanitizing of filenames it is possible that a
specially crafted filename can cause arbitrary commands to be executed.
Multiple buffer overflows can cause the program to crash.
The epiphany web browser had a vulnerability regression that was
caused by fixes to the Mozilla suite. This is specific to
Ubuntu Linux, the Mozilla fix was: USN-155-1.
The ethereal network traffic analyzer has several vulnerabilities,
involving traffic dissectors. Dissectors have buffer overflows,
format string overflows, and crashing/denial of service issues.
There is a vulnerability in the foomatic-filters package. This
vulnerability is due to insufficient checking of command-line parameters
and environment variables in the foomatic-rip filter. This vulnerability
may allow both local and remote attackers to execute arbitrary commands on
the print server with the permissions of the spooler.
Tavis Ormandy of the Gentoo Linux Security Audit Team discovered an integer
overflow in the BFD library, resulting in a heap overflow. A review also
showed that by default, gdb insecurely sources initialization files from
the working directory. Successful exploitation would result in the
execution of arbitrary code on loading a specially crafted object file or
the execution of arbitrary commands.
A format string vulnerability has been discovered in gedit. Calling
the program with specially crafted file names caused a buffer
overflow, which could be exploited to execute arbitrary code with the
privileges of the gedit user.
gettext insecurely creates temporary files in world-writeable directories
with predictable names. A local attacker could create symbolic links in
the temporary files directory, pointing to a valid file somewhere on the
filesystem. When gettext is called, this would result in file access with
the rights of the user running the utility, which could be the root user.
The catchsegv script in the glibc package has a symlink vulnerability
that may allow a local user to overwrite arbitrary
files with the permissions of the user that is running the script.
GnuPG (and other PGP-like systems) suffers from an information leak which could, in some situations, be used by an attacker to obtain plain text from an encrypted message. See this message for a detailed explanation of the problem. "We know of no real-world application that is affected by this type of attack. It is an attack that requires the active participation of someone who holds the actual key required to decrypt a message. Thus, it is not something you are likely to see."
Recently, Trustix Secure Linux discovered a vulnerability in the groff
package. The utility "groffer" created a temporary directory in an
insecure way, which allowed exploitation of a race condition to create
or overwrite files with the privileges of the user invoking the
program.
zgrep in gzip before 1.3.5 does not handle shell metacharacters like '|'
and '&' properly when they occurred in input file names. This could be
exploited to execute arbitrary commands with user privileges if zgrep is
run in an untrusted directory with specially crafted file names.
Michael Krax discovered that ht://Dig fails to validate the 'config'
parameter before displaying an error message containing the parameter.
This flaw could allow an attacker to conduct cross-site scripting
attacks.
A buffer overflow flaw was found in the c-client IMAP client. An attacker
could create a malicious IMAP server that if connected to by a victim could
execute arbitrary code on the client machine.
Ben Burton notified the KDE security team about several tempfile
handling related vulnerabilities in langen2kvtml, a conversion
script for kvoctrain. The script must be manually invoked. The
script uses known filenames in /tmp which allow an local
attacker to overwrite files writeable by the user invoking the
conversion script.
Kate / Kwrite, as shipped with KDE 3.2.x up to including 3.4.0, creates a file backup before saving a modified file. These backup files are created with default permissions, even if the original file had more strict permissions set. See this advisory for more information.
Paul Starzetz has posted an
advisory for yet another kernel vulnerability.
In this case, by using a specially manipulated ELF binary, a local attacker
can compromise the system (via the core dump code) and obtain root access.
This vulnerability affects all kernels from 2.2 through 2.6.12-rc4.
Several vulnerabilities in the 2.6 kernel have been
fixed, including a subthread exec problem (CAN-2005-1913)
and a ia64 ptrace + sigrestore_context problem (CAN-2005-1761).
A number of vulnerabilities have been found in the Linux kernel, including a PPP-related denial of service problem, an integer overflow in the epoll() code, memory corruption in the ELF loader, and exploitable overflows in the ISO9660 code.
The krb5 authentication has a double-free flaw which may be
initiated by a remote unauthenticated attacker.
Also, a single byte heap overflow in the krb5_unparse_name() function
can lead to a denial of service and an information disclosure may
be caused by a malicious telnet server. See
This report for more
information.
Mark Martinec and Robert Lewis discovered a buffer overflow in
Convert::UUlib (before 1.051), a Perl interface to the uulib library, which
may result in the execution of arbitrary code.
Javier Fernández-Sanguino Peña from the Debian Security Audit Project
discovered that the DBI library, the Perl5 database interface, creates
a temporary PID file in an insecure manner. This can be exploited by a
malicious user to overwrite arbitrary files owned by the person
executing the parts of the library.
Szymon Zygmunt and Michal Bartoszkiewicz discovered a memory alignment
error in libgadu (from ekg, console Gadu Gadu client, an instant
messaging program) which is included in gaim, a multi-protocol instant
messaging client, as well. This can not be exploited on the x86
architecture but on others, e.g. on Sparc and lead to a bus error,
in other words a denial of service.
Several buffer overflows have been discovered in libgd's PNG handling
functions.
If an attacker tricked a user into loading a malicious PNG image, they
could leverage this into executing arbitrary code in the context of
the user opening image. Most importantly, this library is commonly
used in PHP. One possible target would be a PHP driven photo website
that lets users upload images. Therefore this vulnerability might lead
to privilege escalation to a web server's privileges.
Multiple buffer overflows in the gd graphics library (libgd) 2.0.21 and
earlier may allow remote attackers to execute arbitrary code via malformed
image files that trigger the overflows due to improper calls to the
gdMalloc function.
Javier Fernandez-Sanguino Pena discovered that this library used the
file /tmp/entropy as a fallback entropy source if a proper source was
not set in the environment variable EGD_PATH. This can potentially
lead to weakened cryptographic operations if an attacker provides a
/tmp/entropy file with known content.
Wouter Hanegraaff discovered that the TIFF library did not
sufficiently validate the "YCbCr subsampling" value in TIFF image
headers. Decoding a malicious image with a zero value resulted in an
arithmetic exception, which caused the program that uses the TIFF
library to crash. This leads to a Denial of Service in server
applications that use libtiff (like the CUPS printing system) and can
cause data loss in, for example, the Evolution email client.
Tavis Ormandy of the Gentoo Linux Security Audit Team discovered a
stack based buffer overflow in the libTIFF library when reading a TIFF
image with a malformed BitsPerSample tag. Successful exploitation would
require the victim to open a specially crafted TIFF image, resulting in the
execution of arbitrary code.
Yuuichi Teranishi discovered a flaw in libxml2 versions prior to 2.6.6.
When fetching a remote resource via FTP or HTTP, libxml2 uses special
parsing routines. These routines can overflow a buffer if passed a very
long URL. If an attacker is able to find an application using libxml2 that
parses remote resources and allows them to influence the URL, then this
flaw could be used to execute arbitrary code.
libxml2 prior to version 2.6.14 has multiple buffer overflow
vulnerabilities, if a local user passes a specially crafted
FTP URL, arbitrary code may be executed.
mod_python has a vulnerability in the publisher handler that may allow
a remote user to use a specially crafted URL to allow access to
objects that should be protected. An information leak can result.
A vulnerability has been discovered in Mozilla and Mozilla Firefox
that allows remote attackers to inject arbitrary Javascript from one
page into the frameset of another site. Thunderbird is not affected
by this.
Erik Sjolund discovered two vulnerabilities in the programs bundled
with ncpfs: there is a potentially exploitable buffer overflow in
ncplogin (CAN-2005-0014), and due to a flaw in nwclient.c, utilities
using the NetWare client functions insecurely access files with
elevated privileges (CAN-2005-0013).
Arjan van de Ven discovered a buffer overflow in rquotad on 64bit
architectures; an improper integer conversion could lead to a buffer
overflow. An attacker with access to an NFS share could send a specially
crafted request which could then lead to the execution of arbitrary code.
Hyper-Threading technology, as used in FreeBSD other operating systems and
implemented on Intel Pentium and other processors, allows local users to
use a malicious thread to create covert channels, monitor the execution of
other threads, and obtain sensitive information such as cryptographic keys,
via a timing attack on memory cache misses. See this LWN article for more information.
There are two vulnerabilities with perl when it is used in a setuid mode. The PERLIO_DEBUG environment variable can be used to overwrite arbitrary files; there is also an associated buffer overflow which can be exploited to gain root access.
PostgreSQL suffers from two vulnerabilities in how databases are set up by default; they allow a local attacker (one with access to the database) to crash the back end and, perhaps, execute code with the privileges of the server process. See this advisory for details and workarounds.
Steven Van Acker has discovered a buffer overflow vulnerability in the
"add_port()" function in Pound 1.8.2+. A remote attacker could send a
request for an overly long hostname parameter, which could lead to the
remote execution of arbitrary code with the rights of the Pound daemon
process.
Multiple format string vulnerabilities in ProFTPD before 1.3.0rc2 allow
attackers to cause a denial of service or obtain sensitive information via
certain inputs to the shutdown message from ftpshut, or the SQLShowInfo
mod_sql directive.
Max Vozeler reported that pstotext calls the GhostScript interpreter on
untrusted PostScript files without specifying the -dSAFER option. An
attacker could craft a malicious PostScript file and entice a user to run
pstotext on it, resulting in the execution of arbitrary commands with the
permissions of the user running pstotext. See this Secunia advisory for more information.
Max Vozeler discovered a vulnerability in pppoe, the PPP over Ethernet
driver from Roaring Penguin. When the program is running setuid root
(which is not the case in a default Debian installation), an attacker
could overwrite any file on the file system.
Shorewall has a vulnerability in which a client that is accepted by
MAC address filtering can bypass other rules, allowing access to
all open services on the firewall.
Charles Morris discovered a race condition in sudo which could lead to
privilege escalation. If /etc/sudoers allowed a user the execution of
selected programs, and this was followed by another line containing
the pseudo-command "ALL", that user could execute arbitrary commands
with sudo by creating symbolic links at a certain time.
Bill Stearns discovered a bug in the way sysreport creates temporary files.
It is possible that a local attacker could obtain sensitive information
about the system when sysreport is run.
The tar utility does not properly filter file names containing
"../", meaning that a hostile archive can, if unpacked by an
unsuspecting user, overwrite any file that is writable by that user. GNU
tar versions 1.13.19 and earlier are vulnerable; unzip through version 5.42
has the same vulnerability.
The rsvp_print function in tcpdump 3.9.1 and earlier allows remote
attackers to cause a denial of service (infinite loop) via a crafted RSVP
packet of length 4. (CAN-2005-1280)
tcpdump 3.8.3 and earlier allows remote attackers to cause a denial of
service (infinite loop) via a crafted BGP packet, which is not properly
handled by RT_ROUTING_INFO, or LDP packet, which is not properly
handled by the ldp_print function. (CAN-2005-1279)
The isis_print function, as called by isoclns_print, in tcpdump 3.9.1 and
earlier allows remote attackers to cause a denial of service (infinite
loop) via a zero length, as demonstrated using a GRE packet.
(CAN-2005-1278)
Multiple vulnerabilities have been found in the Mozilla Thunderbird email
client, as well as the Mozilla Suite and Firefox and Mozilla based other
browsers. Bugs include an anonymous function handling bug, a JavaScript
validation problem, privileged UI code handling DOM nodes, a JavaScript
privilege escalation, a problem with Javascript in XBL controls, improper
handling of child frames, a DOM name code execution vulnerability, and
a base object clone problem.
A bug in Tor allows attackers to view arbitrary memory contents from an
exit server's process space. A remote attacker could exploit the memory
disclosure to gain sensitive information and possibly even private keys.
A denial of service bug was found in the way ucd-snmp uses network stream
protocols. A remote attacker could send a ucd-snmp agent a specially
crafted packet which will cause the agent to crash.
Georgi Guninski discovered
that it was possible to construct Vim 6.3 modelines that execute arbitrary
shell commands by wrapping them in glob() or expand() function calls. If an
attacker tricked an user to open a file with a specially crafted modeline,
he could exploit this to execute arbitrary commands with the user's
privileges.
crontab in Vixie cron 4.1, when running with the -e option, allows local
users to read the cron files of other users by changing the file being
edited to a symlink. NOTE: there is insufficient information to know
whether this is a duplicate of CVE-2001-0235. See also this Security Focus
report.
wget 1.8.x and 1.9.x allows a remote malicious web server to overwrite
certain files via a redirection URL containing a ".." that resolves to the
IP address of the malicious server, which bypasses wget's filtering for
".." sequences.
wget 1.8.x and 1.9.x does not filter or quote control characters when
displaying HTTP responses to the terminal, which may allow remote malicious
web servers to inject terminal escape sequences and execute arbitrary code.
XChat is vulnerable to a stack overflow that may allow a remote attacker to
run arbitrary code. The SOCKS 5 proxy code in XChat is vulnerable to a
remote exploit. Users would have to be using XChat through a SOCKS 5
server, enable SOCKS 5 traversal which is disabled by default and also
connect to an attacker's custom proxy server. This vulnerability may allow
an attacker to run arbitrary code within the context of the user ID of the
XChat client.
Shaun Colley discovered a problem in xine-ui, the xine video player
user interface. A script contained in the package to possibly remedy
a problem or report a bug does not create temporary files in a secure
fashion. This could allow a local attacker to overwrite files with
the privileges of the user invoking xine.
A flaw was discovered in Xpdf in that could allow an attacker to construct
a carefully crafted PDF file that would cause Xpdf to consume all available
disk space in /tmp when opened.
zlib has a buffer overflow vulnerability that can be exploited
by inflation of corrupted files, this can be used to crash zlib
or possibly remotely execute code.
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announcement.
