filters/image-gif.c in Common Unix Printing System (CUPS) 1.1.14 through 1.1.17 does not properly check for zero-length GIF images, which allows remote attackers to execute arbitrary code via modified chunk headers, as demonstrated by nogif.

Multiple vulnerabilities were discovered in the Common Unix Printing System (CUPS). Several of these issues represent the potential for a remote compromise or denial of service. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CAN-2002-1383: Multiple integer overflows allow a remote     attacker to execute arbitrary code via the CUPSd HTTP     interface and the image handling code in CUPS filters.
  - CAN-2002-1366: Race conditions in connection with     /etc/cups/certs/ allow local users with lp privileges to     create or overwrite arbitrary files. This is not present     in the potato version.

  - CAN-2002-1367: This vulnerability allows a remote     attacker to add printers without authentication via a     certain UDP packet, which can then be used to perform     unauthorized activities such as stealing the local root     certificate for the administration server via a 'need     authorization' page.

  - CAN-2002-1368: Negative lengths fed into memcpy() can     cause a denial of service and possibly execute arbitrary     code.

  - CAN-2002-1369: An unsafe strncat() function call     processing the options string allows a remote attacker     to execute arbitrary code via a buffer overflow.

  - CAN-2002-1371: Zero width images allows a remote     attacker to execute arbitrary code via modified chunk     headers.

  - CAN-2002-1372: CUPS does not properly check the return     values of various file and socket operations, which     could allow a remote attacker to cause a denial of     service.

  - CAN-2002-1384: The cupsys package contains some code     from the xpdf package, used to convert PDF files for     printing, which contains an exploitable integer overflow     bug. This is not present in the potato version.

Even though we tried very hard to fix all problems in the packages for potato as well, the packages may still contain other security related problems. Hence, we advise users of potato systems using CUPS to upgrade to woody soon.

iDefense reported several security problems in CUPS that can lead to local and remote root compromise. An integer overflow in the HTTP interface can be used to gain remote access with CUPS privilege. A local file race condition can be used to gain root privilege, although the previous bug must be exploited first. An attacker can remotely add printers to the vulnerable system. A remote DoS can be accomplished due to negative length in the memcpy() call. An integer overflow in image handling code can be used to gain higher privilege. An attacker can gain local root privilege due to a buffer overflow of the 'options' buffer. A design problem can be exploited to gain local root access, however this needs an added printer (which can also be done, as per a previously noted bug). Wrong handling of zero-width images can be abused to gain higher privilege. Finally, a file descriptor leak and DoS due to missing checks of return values of file/socket operations.

MandrakeSoft recommends all users upgrade these CUPS packages immediately.

The remote host is missing the patch for the advisory SUSE-SA:2003:002 (cups).


CUPS is a well known and widely used printing system for unix-like systems. iDFENSE reported several security issues with CUPS that can lead to local and remote root compromise. The following list includes all vulnerabilities:
- integer overflow in HTTP interface to gain remote access with CUPS privileges
- local file race condition to gain root (bug mentioned above has to be exploited first)
- remotely add printers
- remote denial-of-service attack due to negative length in memcpy() call
- integer overflow in image handling code to gain higher privileges
- gain local root due to buffer overflow of 'options' buffer
- design problem to gain local root (needs added printer, see above)
- wrong handling of zero width images can be abused to gain higher privileges
- file descriptor leak and denial-of-service due to missing checks of return values of file/socket operations

Since SUSE 8.1 CUPS is the default printing system.

As a temporary workaround CUPS can be disabled and an alternative printing system like LPRng can be installed instead.

New CUPS packages are available on our FTP servers. Please, install them to fix your system.

Please download the update package for your distribution and verify its integrity by the methods listed in section 3) of this announcement.
Then, install the package using the command 'rpm -Fhv file.rpm' to apply the update.

ID	Name	Product	Family	Severity
15069	Debian DSA-232-1 : cupsys - several vulnerabilities	Nessus	Debian Local Security Checks	critical
13986	Mandrake Linux Security Advisory : cups (MDKSA-2003:001)	Nessus	Mandriva Local Security Checks	critical
13780	SUSE-SA:2003:002: cups	Nessus	SuSE Local Security Checks	critical

Detections

Analytics

CVE-2002-1371

critical

Tenable Plugins

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critical