Here at LWN security headquarters, we have received hundreds of messages
from readers with one crucial security question on their minds: how was
Paris Hilton's T-Mobile account cracked?
Well...OK...maybe we haven't received quite that many messages. But we're
sure people will want to know. Turns out that OSDir
has the answer. Apparently T-Mobile's site has a "secret
answer" mechanism for people who forget their passwords. Ms Hilton's
"secret answer" was her dog's name. Bitten again.
Wherever there is a potential security problem, there is inevitably a
Bruce Schneier column warning about it. In this case, Bruce notes:
Passwords have reached the end of their useful life. Today, they
only work for low-security applications. The secret question is
just one manifestation of that fact.
Passwords may well be heading toward the end of their useful life, but
"secret answers" are not necessarily a demonstration of that fact. Many
web sites (or other interfaces requiring confirmation) go out of their way
to prevent the use of insecure passwords. Some site developers put
considerable effort into creating novel rules for passwords. Then they add a "secret
answer" mechanism which bypasses all of that.
The real issue here, perhaps, is that an authentication interface should
actually control access to the resources it protects. Back doors are never
good for the security of a system, and a "secret answer" scheme is really
just a form of back door. If you provide a way around your password
interface, you should not be surprised if attackers use it.
MozillaZine reports
that IDN support will not be disabled. The details of the new short term
solution are available. "Darin Fisher, network supremo, has
pulled it out of the bag and come up with a less drastic short-term
solution to the IDN problem. It has just been checked in for all three
upcoming releases. Read about it over in bug 282270, but basically IDN will
still work, but all occurrences of IDN domains in the browser UI (URL bar,
security info etc.) will be the punycode form. There is a pref to re-enable
full IDN - set "network.IDN_show_punycode" to false. As with the previous
plan, this preference will be set to true in all official builds."
Meanwhile the search for a long term solution continues.
Ulf Härnhammar from the Debian Security Audit Project discovered a
format string vulnerability in bidwatcher, a tool for watching and
bidding on eBay auctions. This problem can be triggered remotely by a
web server of eBay, or someone pretending to be eBay, sending certain
data back. As of version 1.3.17 the program uses cURL and is not
vulnerable anymore.
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.
The Gaim client freezes when receiving certain invalid messages and crashes
when receiving specific malformed HTML. See this Secunia Advisory for
additional information.
Tavis Ormandy of the Gentoo Linux Security Audit Team has identified a
format string vulnerability in the gprostats utility. An attacker could
exploit the vulnerability by performing a specially crafted FTP transfer,
the resulting ProFTPD transfer log could potentially trigger the execution
of arbitrary code when parsed by GProFTPD.
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.
Midnight commander has multiple vulnerabilities including
format string vulnerabilities, buffer overflows, a buffer underflow,
and a memory deallocation error. An attacker can use these to
run arbitrary code with the permission of the user.
Two vulnerabilities have been discovered in the PSCP and PSFTP clients,
which can be triggered by the SFTP server itself. See this iDEFENSE advisory for details.
Handling of certain DNS responses trigger assertion failures. By returning
a specially crafted DNS response an attacker could cause Squid to crash by
triggering an assertion failure.
The patch for integer overflow vulnerabilities in Xpdf 2.0 and 3.0
(CAN-2004-0888) is incomplete for 64-bit architectures on certain Linux
distributions such as Red Hat, which could leave Xpdf users exposed to the
original vulnerabilities.
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 flaw in the alsa mixer code was discovered that caused stack execution
protection to be disabled for the libasound.so library. The effect of this
flaw is that stack execution protection, through NX or Exec-Shield, would
be disabled for any application linked to libasound.
cyrus-sasl has a vulnerability involving a buffer overflow
in the digestmda5.c file. A remote attacker may be able
to compromise the system. Also, a local user may be able to
exploit a vulnerability by using the SASL_PATH environment
variable.
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.
Max Vozeler discovered an integer overflow in camel-lock-helper. A
user-supplied length value was not validated, so that a value of -1
caused a buffer allocation of 0 bytes; this buffer was then filled by
an arbitrary amount of user-supplied data. A local attacker or a malicious
POP3 server could exploit this to execute arbitrary code with root
privileges (because camel-lock-helper is installed as setuid root).
The f2c fortran to C translator has a vulnerability due to
insecure opening of temporary files. A local attacker can use this
to launch a symlink attack.
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.
The gdk-pixbuf and gtk2 libraries contain vulnerabilities in their handling of BMP and XPM files which can lead to denial of service and, potentially, code execution attacks.
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.
Silvio Cesare discovered a potential information leak in glibc. It allows
LD_DEBUG on SUID binaries where it should not be allowed. This has various
security implications, which may be used to gain confidential information.
An attacker can gain the list of symbols a SUID application uses and their
locations and can then use a trojaned library taking precedence over those
symbols to gain information or perform further exploitation.
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.
Several scripts packaged with gnome-vfs, using its "extfs" capability, have security flaws. These scripts tend not to be used on many systems, but their presence can still be a threat.
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.
GtkHTML is the HTML rendering widget used by the Evolution mail reader.
GtkHTML supplied with versions of Evolution prior to 1.2.4 contain a bug
when handling HTML messages. Alan Cox discovered that certain malformed
messages could cause the Evolution mail component to crash.
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.
According to this iDEFENSE advisory,
ImageMagick is vulnerable to a heap overflow when decoding .psd image
files. This could be remotely exploited allowing an attacker to execute
arbitrary code.
Erik Sjolund discovered a buffer overflow in fliccd which is part of
kdeedu, edutainment applications for KDE. An attacker could exploit this
vulnerability to execute code with elevated privileges. If fliccd does not
run as daemon remote exploitation of this vulnerability is not possible.
Thiago Macieira discovered a vulnerability in the kioslave library,
which is part of kdelibs, which allows a remote attacker to execute
arbitrary FTP commands via an ftp:// URL that contains an URL-encoded
newline before the FTP command.
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.
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.
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.
lighttpd uses file extensions to determine which elements are programs
that should be executed and which are static pages that should be sent
as-is. By appending %00 to the filename, you can evade the extension
detection mechanism while still accessing the file. A remote attacker
could send specific queries and access the source of scripts that should
have been executed as CGI or FastCGI applications.
Michael Kerrisk noticed an insufficient permission checking in the shmctl()
function. Any process was permitted to lock/unlock any System V shared
memory segment that fell within the the RLIMIT_MEMLOCK limit (that is the
maximum size of shared memory that unprivileged users can acquire). This
allowed am unprivileged user process to unlock locked memory of other
processes, thereby allowing them to be swapped out. Usually locked shared
memory is used to store passphrases and other sensitive content which must
not be written to the swap space (where it could be read out even after a
reboot). (CAN-2005-0176)
OGAWA Hirofumi noticed that the table sizes in nls_ascii.c were incorrectly
set to 128 instead of 256. This caused a buffer overflow in some cases
which could be exploited to crash the kernel. (CAN-2005-177)
A race condition was found in the terminal handling of the "setsid()" function, which is used to start new process sessions. (CAN-2005-178)
Trustix Secure Linux discovered a vulnerability in a supplemental script of
the lvm10 package. The program "lvmcreate_initrd" created a temporary
directory in an insecure way, which could allow a symlink attack to create
or overwrite arbitrary files with the privileges of the user invoking the
program.
Florian Weimer discovered a cross-site scripting vulnerability in
mailman's automatically generated error messages. An attacker could
craft an URL containing JavaScript (or other content embedded into
HTML) which triggered a mailman error page. When an unsuspecting user
followed this URL, the malicious content was copied unmodified to the
error page and executed in the context of this page.
The "private" module in the mailman mailing list manager fails to sanitize path names adequately. An attacker could exploit this vulnerability to retrieve private information, including passwords and private list archives.
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 was discovered in mpg321, a command-line mp3 player,
whereby user-supplied strings were passed to printf(3) unsafely. This
vulnerability could be exploited by a remote attacker to overwrite
memory, and possibly execute arbitrary code. In order for this
vulnerability to be exploited, mpg321 would need to play a malicious
mp3 file (including via HTTP streaming).
Several problems have been discovered in MySQL. Oleksandr Byelkin noticed
that ALTER TABLE ... RENAME checks CREATE/INSERT rights of the old table
instead of the new one. (CAN-2004-0835) Lukasz Wojtow noticed a buffer
overrun in the mysql_real_connect function. (CAN-2004-0836) Dean Ellis
noticed that multiple threads ALTERing the same (or different) MERGE tables
to change the UNION can cause the server to crash or stall. (CAN-2004-0837)
Javier Fernández-Sanguino Peña noticed that the "mysqlaccess" program
created temporary files in an insecure manner. This could allow a
symbolic link attack to create or overwrite arbitrary files with the
privileges of the user invoking the program.
Jonathan Rockway discovered that NASM-0.98.38 has an unprotected
vsprintf() to an array in preproc.c. This code vulnerability may lead
to a buffer overflow and potential execution of arbitrary code.
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).
"Vlad902" discovered a vulnerability in the rwhod program that can be
used to crash the listening process. The broadcasting one is
unaffected. This vulnerability only affects little endian
architectures (i.e. on Debian: alpha, arm, alpha, ia64, i386, mipsel
and s390).
Michal Zalewski discovered a bug in the netkit-telnet server (telnetd)
whereby a remote attacker could cause the telnetd process to free an
invalid pointer. This causes the telnet server process to crash, leading
to a straightforward denial of service (inetd will disable the service if
telnetd is crashed repeatedly), or possibly the execution of arbitrary code
with the privileges of the telnetd process (by default, the 'telnetd'
user).
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.
The der_chop script in openssl has a temp file vulnerability that may allow
an attacker to overwrite arbitrary files with the permissions that
the script is running under.
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.
PHP has an out of bounds memory write access vulnerability and
an integer overflow/underflow problem. See the PHP 4.3.10 Release Announcement for details.
A vulnerability was reported in PHP in the cURL functions. A script can bypass the 'open_basedir' directory setting. See this SecurityTracker Alert for more information.
Jean-Samuel Reynaud noticed a programming error in the IPv6 handling code
of Postfix when /proc/net/if_inet6 is not available. If "permit_mx_backup"
was enabled in the "smtpd_recipient_restrictions", Postfix turned into an
open relay, i. e. erroneously permitted the delivery of arbitrary mail to
any MX host which has an IPv6 address.
postgresql has a vulnerability in which the EXECUTE privilege may
not be checked on custom functions. This may allow any database user to
circumvent the EXECUTE restriction on functions.
Python versions 2.2 and 2.3 has a vulnerability in the
SimpleXMLRPCServer module which may allow
remote users to read or change function internals via the
im_* and func_* attributes.
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.
The upstream developers of Ruby have corrected a problem in the CGI
module for this language. Specially crafted requests could cause an
infinite loop and thus cause the program to eat up cpu cycles.
sharutils contains two buffer overflows. Ulf Harnhammar discovered a buffer
overflow in shar.c, where the length of data returned by the wc command is
not checked. Florian Schilhabel discovered another buffer overflow in
unshar.c. An attacker could exploit these vulnerabilities to execute
arbitrary code as the user running one of the sharutils programs.
SpamAssassin contains an unspecified Denial of Service vulnerability. By
sending a specially crafted message an attacker could cause a Denial of
Service attack against the SpamAssassin service.
Several vulnerabilities have been discovered in Squid, including cache
pollution/poisoning via HTTP response splitting, larger than normal WCCP
packet could overflow a buffer, and more.
Subversion has a remote Denial of Service vulnerability
that may allow a server that runs svnserve to execute
arbitrary code. See this advisory for more information.
Versions of sudo prior to 1.6.8p2 fail to properly sanitize the environment prior to running shell scripts; this failure can be exploited by a sudo user to subvert scripts and obtain shell access. See the 1.6.8p2 announcement for more information.
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.
A bug was found in the way Thunderbird handled cookies when loading content
over HTTP regardless of the user's preference. It is possible that a
particular user could be tracked through the use of malicious mail messages
which load content over HTTP.
The tiff library contains several buffer overflows which may be exploited
by way of maliciously-crafted image files. See this advisory for more information.
Ulf Härnhammar from the Debian Security Audit Project discovered a
problem in typespeed, a touch-typist trainer disguised as game. This
could lead to a local attacker executing arbitrary code as group
games.
The uw-imap package, prior to version 2004b, contains a vulnerability which can enable a remote attacker to bypass the authentication mechanism. This bug only affects CRAM-MD5 authentication, which is not enabled on all distributions.
A new set of modeline-related vulnerabilities has been discovered in versions of vim prior to 6.3-r2. These vulnerabilities could conceivably be exploited by a local user to obtain the privileges of another user.
Javier Fernández-Sanguino Peña noticed that the auxiliary scripts
"tcltags" and "vimspell.sh" created temporary files in an insecure
manner. This could allow a symbolic link attack to create or overwrite
arbitrary files with the privileges of the user invoking the script
(either by calling it directly or by execution through vim).
wpa_supplicant contains a possible buffer overflow due to the lacking
validation of received EAPOL-Key frames. An attacker could cause the crash
of wpa_supplicant using a specially crafted packet.
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.
xpdf has a
potential buffer overflow problem caused by insufficient input validation.
A specially crafted PDF file can allow an
attacker to execute code with privileges of the xpdf user.
Several xpdf integer overflow vulnerabilities can be exploited via a
mal-formed PDF document. Similar vulnerabilities can be found in kpdf and
in cupsys which share code. Additional information can be found in this KDE security advisory.
iDEFENSE Labs has announced the launch of a community site. This site serves as a
repository for sharing research and development with the security
community, including the release of free software tools.
The Call for Papers has been announced for the RECON conference. RECON is
a security conference taking place in downtown Montreal June 17 - 19.
Papers must be submitted by April 15, 2005.
