XScreenSaver getpwuid() function authentication bypass
| xscreensaver-getpwuid-authentication-bypass (34054) |  Medium Risk |
Description:
XScreenSaver could allow a local attacker to bypass authentication, caused by the improper parsing of a call to the getpwuid() function. If the application is using a remote directory service for login during a network outage, a local attacker could exploit this vulnerability to crash the application to unlock the screen and gain unauthorized access to the victim's system.
Platforms Affected:
- Canonical, Ubuntu 6.06 LTS
- Canonical, Ubuntu 6.10
- Canonical, Ubuntu 7.04
- Gentoo, Linux
- JWZ, XScreenSaver 4.10
- MandrakeSoft, Mandrake Linux 2007
- MandrakeSoft, Mandrake Linux 2007 X86_64
- MandrakeSoft, Mandrake Linux 2007.1
- MandrakeSoft, Mandrake Linux 2007.1 X86_64
- MandrakeSoft, Mandrake Linux 2008.0 X86_64
- MandrakeSoft, Mandrake Linux Corporate Server 3.0
- MandrakeSoft, Mandrake Linux Corporate Server 3.0 X86_64
- RedHat, Enterprise Linux 2.1 AS
- RedHat, Enterprise Linux 2.1 ES
- RedHat, Enterprise Linux 2.1 WS
- RedHat, Enterprise Linux 3 WS
- RedHat, Enterprise Linux 3 Desktop
- RedHat, Enterprise Linux 3 AS
- RedHat, Enterprise Linux 3 ES
- RedHat, Enterprise Linux 4 AS
- RedHat, Enterprise Linux 4 Desktop
- RedHat, Enterprise Linux 4 WS
- RedHat, Enterprise Linux 4 ES
- RedHat, Linux Advanced Workstation 2.1 Itanium
Remedy:
Upgrade to the latest version of XScreenSaver (5.02 or later), available from the XScreenSaver Web site. See References.
For Red Hat Linux (xscreensaver):
Refer to RHSA-2007:0322-4 for patch, upgrade, or suggested workaround information. See References.
For Gentoo Linux (XScreenSaver):
Refer to GLSA 200705-14 for patch, upgrade, or suggested workaround information. See References.
For Ubuntu Linux (xscreensaver):
Refer to USN-474-1 for patch, upgrade, or suggested workaround information. See References.
For Mandriva Linux (xscreensaver):
Refer to MDKSA-2007:097 for patch, upgrade, or suggested workaround information. See References.
For other distributions:
Contact your vendor for upgrade or patch information.
Consequences:
Bypass Security
References:
- Red Hat Bugzilla Bug 237003, CVE-2007-1859 xscreensaver authentication bypass at https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=237003.
- XScreenSaver Web site, XScreenSaver at http://www.jwz.org/xscreensaver/.
- ASA-2007-264: XScreenSaver security update (RHSA-2007-0322)
- BID-23783: Xscreensaver Local Denial Of Service Vulnerability
- CVE-2007-1859: XScreenSaver 4.10, when using a remote directory service for credentials, does not properly handle the results from the getpwuid function in drivers/lock.c when there is no network connectivity, which causes XScreenSaver to crash and unlock the screen and allows local users to bypass authentication.
- GLSA-200705-14: XScreenSaver: Privilege escalation
- MDKSA-2007:097: Updated xscreensaver packages fix vulnerability
- RHSA-2007-0322: Important: xscreensaver security update
- SA25065: XScreenSaver "getpwuid()" Authentication Bypass Weakness
- SECTRACK ID: 1017996: XScreenSaver LDAP Authentication Error Lets Physically Local Users Bypass the Password Feature
- USN-474-1: xscreensaver vulnerability
Reported:
May 02, 2007
The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (IBM Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.
For corrections or additions please email xforce@iss.net