ID CVE-2011-0727
Summary GNOME Display Manager (gdm) 2.x before 2.32.1 allows local users to change the ownership of arbitrary files via a symlink attack on a (1) dmrc or (2) face icon file under /var/cache/gdm/.
References
Vulnerable Configurations
  • cpe:2.3:a:gnome:gdm:2.0
    cpe:2.3:a:gnome:gdm:2.0
  • cpe:2.3:a:gnome:gdm:2.2
    cpe:2.3:a:gnome:gdm:2.2
  • cpe:2.3:a:gnome:gdm:2.3
    cpe:2.3:a:gnome:gdm:2.3
  • cpe:2.3:a:gnome:gdm:2.4
    cpe:2.3:a:gnome:gdm:2.4
  • cpe:2.3:a:gnome:gdm:2.5
    cpe:2.3:a:gnome:gdm:2.5
  • cpe:2.3:a:gnome:gdm:2.6
    cpe:2.3:a:gnome:gdm:2.6
  • cpe:2.3:a:gnome:gdm:2.8
    cpe:2.3:a:gnome:gdm:2.8
  • cpe:2.3:a:gnome:gdm:2.13
    cpe:2.3:a:gnome:gdm:2.13
  • cpe:2.3:a:gnome:gdm:2.14
    cpe:2.3:a:gnome:gdm:2.14
  • cpe:2.3:a:gnome:gdm:2.15
    cpe:2.3:a:gnome:gdm:2.15
  • cpe:2.3:a:gnome:gdm:2.16
    cpe:2.3:a:gnome:gdm:2.16
  • cpe:2.3:a:gnome:gdm:2.17
    cpe:2.3:a:gnome:gdm:2.17
  • cpe:2.3:a:gnome:gdm:2.18
    cpe:2.3:a:gnome:gdm:2.18
  • cpe:2.3:a:gnome:gdm:2.19
    cpe:2.3:a:gnome:gdm:2.19
  • cpe:2.3:a:gnome:gdm:2.20
    cpe:2.3:a:gnome:gdm:2.20
  • cpe:2.3:a:gnome:gdm:2.21
    cpe:2.3:a:gnome:gdm:2.21
  • cpe:2.3:a:gnome:gdm:2.22
    cpe:2.3:a:gnome:gdm:2.22
  • cpe:2.3:a:gnome:gdm:2.23
    cpe:2.3:a:gnome:gdm:2.23
  • cpe:2.3:a:gnome:gdm:2.24
    cpe:2.3:a:gnome:gdm:2.24
  • cpe:2.3:a:gnome:gdm:2.25
    cpe:2.3:a:gnome:gdm:2.25
  • cpe:2.3:a:gnome:gdm:2.26
    cpe:2.3:a:gnome:gdm:2.26
  • cpe:2.3:a:gnome:gdm:2.27
    cpe:2.3:a:gnome:gdm:2.27
  • cpe:2.3:a:gnome:gdm:2.28
    cpe:2.3:a:gnome:gdm:2.28
  • cpe:2.3:a:gnome:gdm:2.29
    cpe:2.3:a:gnome:gdm:2.29
  • cpe:2.3:a:gnome:gdm:2.30
    cpe:2.3:a:gnome:gdm:2.30
  • cpe:2.3:a:gnome:gdm:2.31
    cpe:2.3:a:gnome:gdm:2.31
  • cpe:2.3:a:gnome:gdm:2.32
    cpe:2.3:a:gnome:gdm:2.32
CVSS
Base: 6.9 (as of 01-04-2011 - 09:00)
Impact:
Exploitability:
CWE CWE-59
CAPEC
  • Symlink Attack
    An attacker positions a symbolic link in such a manner that the targeted user or application accesses the link's endpoint, assuming that it is accessing a file with the link's name. The endpoint file may be either output or input. If the file is output, the result is that the endpoint is modified, instead of a file at the intended location. Modifications to the endpoint file may include appending, overwriting, corrupting, changing permissions, or other modifications. In some variants of this attack the attacker may be able to control the change to a file while in other cases they cannot. The former is especially damaging since the attacker may be able to grant themselves increased privileges or insert false information, but the latter can also be damaging as it can expose sensitive information or corrupt or destroy vital system or application files. Alternatively, the endpoint file may serve as input to the targeted application. This can be used to feed malformed input into the target or to cause the target to process different information, possibly allowing the attacker to control the actions of the target or to cause the target to expose information to the attacker. Moreover, the actions taken on the endpoint file are undertaken with the permissions of the targeted user or application, which may exceed the permissions that the attacker would normally have.
  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
Access
VectorComplexityAuthentication
LOCAL MEDIUM NONE
Impact
ConfidentialityIntegrityAvailability
COMPLETE COMPLETE COMPLETE
nessus via4
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-1099-1.NASL
    description Sebastian Krahmer discovered that GDM (GNOME Display Manager) did not properly drop privileges when handling the cache directories used to store users' dmrc and face icon files. This could allow a local attacker to change the ownership of arbitrary files, thereby gaining root privileges. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-12-01
    plugin id 53238
    published 2011-03-31
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=53238
    title Ubuntu 9.10 / 10.04 LTS / 10.10 : gdm vulnerability (USN-1099-1)
  • NASL family Scientific Linux Local Security Checks
    NASL id SL_20110329_GDM_ON_SL6_X.NASL
    description The GNOME Display Manager (GDM) provides the graphical login screen, shown shortly after boot up, log out, and when user-switching. A race condition flaw was found in the way GDM handled the cache directories used to store users' dmrc and face icon files. A local attacker could use this flaw to trick GDM into changing the ownership of an arbitrary file via a symbolic link attack, allowing them to escalate their privileges. (CVE-2011-0727) We would like to thank Sebastian Krahmer of the SuSE Security Team for reporting this issue.
    last seen 2019-02-21
    modified 2018-12-31
    plugin id 60998
    published 2012-08-01
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=60998
    title Scientific Linux Security Update : gdm on SL6.x i386/x86_64
  • NASL family Mandriva Local Security Checks
    NASL id MANDRIVA_MDVSA-2011-070.NASL
    description A vulnerability has been found and corrected in gdm : GNOME Display Manager (gdm) 2.x before 2.32.1 allows local users to change the ownership of arbitrary files via a symlink attack on a (1) dmrc or (2) face icon file under /var/cache/gdm/ (CVE-2011-0727). The updated packages have been patched to correct this issue.
    last seen 2019-02-21
    modified 2018-07-19
    plugin id 53349
    published 2011-04-11
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=53349
    title Mandriva Linux Security Advisory : gdm (MDVSA-2011:070)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2011-4351.NASL
    description This update addresses a local root exploit for GDM. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2015-10-20
    plugin id 53437
    published 2011-04-15
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=53437
    title Fedora 13 : gdm-2.30.2-2.fc13 (2011-4351)
  • NASL family Oracle Linux Local Security Checks
    NASL id ORACLELINUX_ELSA-2011-0395.NASL
    description From Red Hat Security Advisory 2011:0395 : Updated gdm packages that fix one security issue are now available for Red Hat Enterprise Linux 6. The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. The GNOME Display Manager (GDM) provides the graphical login screen, shown shortly after boot up, log out, and when user-switching. A race condition flaw was found in the way GDM handled the cache directories used to store users' dmrc and face icon files. A local attacker could use this flaw to trick GDM into changing the ownership of an arbitrary file via a symbolic link attack, allowing them to escalate their privileges. (CVE-2011-0727) Red Hat would like to thank Sebastian Krahmer of the SuSE Security Team for reporting this issue. All users should upgrade to these updated packages, which contain a backported patch to correct this issue. GDM must be restarted for this update to take effect. Rebooting achieves this, but changing the runlevel from 5 to 3 and back to 5 also restarts GDM.
    last seen 2019-02-21
    modified 2018-07-18
    plugin id 68241
    published 2013-07-12
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=68241
    title Oracle Linux 6 : gdm (ELSA-2011-0395)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2011-4335.NASL
    description This update addresses a local root exploit. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-07-12
    plugin id 53265
    published 2011-04-04
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=53265
    title Fedora 14 : gdm-2.32.1-2.fc14 (2011-4335)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_11_3_GDM-110330.NASL
    description Local users could trick gdm into changing ownership of arbitrary files by placing symlinks in the user session cache (CVE-2011-0727).
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 75511
    published 2014-06-13
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=75511
    title openSUSE Security Update : gdm (openSUSE-SU-2011:0275-1)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_11_4_GDM-110330.NASL
    description Local users could trick gdm into changing ownership of arbitrary files by placing symlinks in the user session cache (CVE-2011-0727).
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 75847
    published 2014-06-13
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=75847
    title openSUSE Security Update : gdm (openSUSE-SU-2011:0275-1)
  • NASL family Gentoo Local Security Checks
    NASL id GENTOO_GLSA-201412-09.NASL
    description The remote host is affected by the vulnerability described in GLSA-201412-09 (Multiple packages, Multiple vulnerabilities fixed in 2011) Vulnerabilities have been discovered in the packages listed below. Please review the CVE identifiers in the Reference section for details. FMOD Studio PEAR Mail LVM2 GnuCash xine-lib Last.fm Scrobbler WebKitGTK+ shadow tool suite PEAR unixODBC Resource Agents mrouted rsync XML Security Library xrdb Vino OProfile syslog-ng sFlow Toolkit GNOME Display Manager libsoup CA Certificates Gitolite QtCreator Racer Impact : A context-dependent attacker may be able to gain escalated privileges, execute arbitrary code, cause Denial of Service, obtain sensitive information, or otherwise bypass security restrictions. Workaround : There are no known workarounds at this time.
    last seen 2019-02-21
    modified 2017-04-15
    plugin id 79962
    published 2014-12-15
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=79962
    title GLSA-201412-09 : Multiple packages, Multiple vulnerabilities fixed in 2011
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DSA-2205.NASL
    description Sebastian Krahmer discovered that GDM 3, the GNOME Display Manager, does not properly drop privileges when manipulating files related to the logged-in user. As a result, local users can gain root privileges. The oldstable distribution (lenny) does not contain a gdm3 package. The gdm package is not affected by this issue.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 53198
    published 2011-03-29
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=53198
    title Debian DSA-2205-1 : gdm3 - privilege escalation
  • NASL family FreeBSD Local Security Checks
    NASL id FREEBSD_PKG_C6FBD44759ED11E08D040015F2DB7BDE.NASL
    description Sebastian Krahmer reports : It was discovered that the GNOME Display Manager (gdm) cleared the cache directory, which is owned by an unprivileged user, with the privileges of the root user. A race condition exists in gdm where a local user could take advantage of this by writing to the cache directory between ending the session and the signal to clean up the session, which could lead to the execution of arbitrary code as the root user.
    last seen 2019-02-21
    modified 2018-11-23
    plugin id 53217
    published 2011-03-30
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=53217
    title FreeBSD : gdm -- privilege escalation vulnerability (c6fbd447-59ed-11e0-8d04-0015f2db7bde)
  • NASL family Red Hat Local Security Checks
    NASL id REDHAT-RHSA-2011-0395.NASL
    description Updated gdm packages that fix one security issue are now available for Red Hat Enterprise Linux 6. The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. The GNOME Display Manager (GDM) provides the graphical login screen, shown shortly after boot up, log out, and when user-switching. A race condition flaw was found in the way GDM handled the cache directories used to store users' dmrc and face icon files. A local attacker could use this flaw to trick GDM into changing the ownership of an arbitrary file via a symbolic link attack, allowing them to escalate their privileges. (CVE-2011-0727) Red Hat would like to thank Sebastian Krahmer of the SuSE Security Team for reporting this issue. All users should upgrade to these updated packages, which contain a backported patch to correct this issue. GDM must be restarted for this update to take effect. Rebooting achieves this, but changing the runlevel from 5 to 3 and back to 5 also restarts GDM.
    last seen 2019-02-21
    modified 2018-11-26
    plugin id 53207
    published 2011-03-29
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=53207
    title RHEL 6 : gdm (RHSA-2011:0395)
redhat via4
advisories
bugzilla
id 688323
title CVE-2011-0727 gdm: privilege escalation vulnerability
oval
AND
  • OR
    • comment Red Hat Enterprise Linux 6 Client is installed
      oval oval:com.redhat.rhba:tst:20111656001
    • comment Red Hat Enterprise Linux 6 Server is installed
      oval oval:com.redhat.rhba:tst:20111656002
    • comment Red Hat Enterprise Linux 6 Workstation is installed
      oval oval:com.redhat.rhba:tst:20111656003
    • comment Red Hat Enterprise Linux 6 ComputeNode is installed
      oval oval:com.redhat.rhba:tst:20111656004
  • OR
    • AND
      • comment gdm is earlier than 1:2.30.4-21.el6_0.1
        oval oval:com.redhat.rhsa:tst:20110395005
      • comment gdm is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110395006
    • AND
      • comment gdm-libs is earlier than 1:2.30.4-21.el6_0.1
        oval oval:com.redhat.rhsa:tst:20110395007
      • comment gdm-libs is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110395008
    • AND
      • comment gdm-plugin-fingerprint is earlier than 1:2.30.4-21.el6_0.1
        oval oval:com.redhat.rhsa:tst:20110395009
      • comment gdm-plugin-fingerprint is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110395010
    • AND
      • comment gdm-plugin-smartcard is earlier than 1:2.30.4-21.el6_0.1
        oval oval:com.redhat.rhsa:tst:20110395013
      • comment gdm-plugin-smartcard is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110395014
    • AND
      • comment gdm-user-switch-applet is earlier than 1:2.30.4-21.el6_0.1
        oval oval:com.redhat.rhsa:tst:20110395011
      • comment gdm-user-switch-applet is signed with Red Hat redhatrelease2 key
        oval oval:com.redhat.rhsa:tst:20110395012
rhsa
id RHSA-2011:0395
released 2011-03-28
severity Moderate
title RHSA-2011:0395: gdm security update (Moderate)
rpms
  • gdm-1:2.30.4-21.el6_0.1
  • gdm-libs-1:2.30.4-21.el6_0.1
  • gdm-plugin-fingerprint-1:2.30.4-21.el6_0.1
  • gdm-plugin-smartcard-1:2.30.4-21.el6_0.1
  • gdm-user-switch-applet-1:2.30.4-21.el6_0.1
refmap via4
bid 47063
confirm
debian DSA-2205
fedora
  • FEDORA-2011-4335
  • FEDORA-2011-4351
mandriva MDVSA-2011:070
mlist [gdm-list] 20110328 GDM 2.32.1 released
sectrack 1025264
secunia
  • 43714
  • 43854
  • 44021
ubuntu USN-1099-1
vupen
  • ADV-2011-0786
  • ADV-2011-0787
  • ADV-2011-0797
  • ADV-2011-0847
  • ADV-2011-0911
xf display-manager-priv-escalation(66377)
Last major update 29-04-2011 - 00:00
Published 31-03-2011 - 18:55
Last modified 16-08-2017 - 21:33
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