In X.Org Server (aka xserver and xorg-server) before 1.19.4, an attacker authenticated to an X server with the X shared memory extension enabled can cause aborts of the X server or replace shared memory segments of other X clients in the same session.

According to the versions of the xorg-x11-server packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - A flaw was found in xorg-x11-server before 1.20.3. An     incorrect permission check for -modulepath and -logfile     options when starting Xorg. X server allows     unprivileged users with the ability to log in to the     system via physical console to escalate their     privileges and run arbitrary code under root     privileges.(CVE-2018-14665)

  - In the X.Org X server before 2017-06-19, a user     authenticated to an X Session could crash or execute     code in the context of the X Server by exploiting a     stack overflow in the endianness conversion of X     Events.(CVE-2017-10971)

  - In X.Org Server (aka xserver and xorg-server) before     1.19.4, an attacker authenticated to an X server with     the X shared memory extension enabled can cause aborts     of the X server or replace shared memory segments of     other X clients in the same session.(CVE-2017-13721)

  - It was found that xorg-x11-server before 1.19.0     including uses memcmp() to check the received MIT     cookie against a series of valid cookies. If the cookie     is correct, it is allowed to attach to the Xorg     session. Since most memcmp() implementations return     after an invalid byte is seen, this causes a time     difference between a valid and invalid byte, which     could allow an efficient brute force     attack.(CVE-2017-2624)

  - Uninitialized data in endianness conversion in the     XEvent handling of the X.Org X Server before 2017-06-19     allowed authenticated malicious users to access     potentially privileged data from the X     server.(CVE-2017-10972)

  - xorg-x11-server before 1.19.5 had wrong extra length     check in ProcXIChangeHierarchy function allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12178)

  - xorg-x11-server before 1.19.5 was missing extra length     validation in ProcEstablishConnection function allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12176)

  - xorg-x11-server before 1.19.5 was missing length     validation in MIT-SCREEN-SAVER extension allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12185)

  - xorg-x11-server before 1.19.5 was missing length     validation in RENDER extension allowing malicious X     client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12187)

  - xorg-x11-server before 1.19.5 was missing length     validation in XFIXES extension allowing malicious X     client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12183)

  - xorg-x11-server before 1.19.5 was missing length     validation in XFree86 DGA extension allowing malicious     X client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12181)

  - xorg-x11-server before 1.19.5 was missing length     validation in XFree86 DRI extension allowing malicious     X client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12182)

  - xorg-x11-server before 1.19.5 was missing length     validation in XFree86 VidModeExtension allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12180)

  - xorg-x11-server before 1.19.5 was missing length     validation in XINERAMA extension allowing malicious X     client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12184)

  - xorg-x11-server before 1.19.5 was missing length     validation in X-Resource extension allowing malicious X     client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12186)

  - xorg-x11-server before 1.19.5 was vulnerable to integer     overflow in (S)ProcXIBarrierReleasePointer functions     allowing malicious X client to cause X server to crash     or possibly execute arbitrary code.(CVE-2017-12179)

  - xorg-x11-server before 1.19.5 was vulnerable to integer     overflow in ProcDbeGetVisualInfo function allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12177)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the xorg-x11-server packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - xorg-x11-server before 1.19.5 was vulnerable to integer     overflow in ProcDbeGetVisualInfo function allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12177)

  - xorg-x11-server before 1.19.5 had wrong extra length     check in ProcXIChangeHierarchy function allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12178)

  - xorg-x11-server before 1.19.5 was vulnerable to integer     overflow in (S)ProcXIBarrierReleasePointer functions     allowing malicious X client to cause X server to crash     or possibly execute arbitrary code.(CVE-2017-12179)

  - xorg-x11-server before 1.19.5 was missing length     validation in XFree86 VidModeExtension allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12180)

  - xorg-x11-server before 1.19.5 was missing length     validation in XFree86 DGA extension allowing malicious     X client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12181)

  - xorg-x11-server before 1.19.5 was missing length     validation in XFree86 DRI extension allowing malicious     X client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12182)

  - xorg-x11-server before 1.19.5 was missing length     validation in XFIXES extension allowing malicious X     client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12183)

  - xorg-x11-server before 1.19.5 was missing length     validation in XINERAMA extension allowing malicious X     client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12184)

  - xorg-x11-server before 1.19.5 was missing length     validation in MIT-SCREEN-SAVER extension allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12185)

  - xorg-x11-server before 1.19.5 was missing length     validation in X-Resource extension allowing malicious X     client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12186)

  - xorg-x11-server before 1.19.5 was missing length     validation in RENDER extension allowing malicious X     client to cause X server to crash or possibly execute     arbitrary code.(CVE-2017-12187)

  - In X.Org Server (aka xserver and xorg-server) before     1.19.4, an attacker authenticated to an X server with     the X shared memory extension enabled can cause aborts     of the X server or replace shared memory segments of     other X clients in the same session.(CVE-2017-13721)

  - It was found that xorg-x11-server before 1.19.0     including uses memcmp() to check the received MIT     cookie against a series of valid cookies. If the cookie     is correct, it is allowed to attach to the Xorg     session. Since most memcmp() implementations return     after an invalid byte is seen, this causes a time     difference between a valid and invalid byte, which     could allow an efficient brute force     attack.(CVE-2017-2624)

  - A flaw was found in xorg-x11-server before 1.20.3. An     incorrect permission check for -modulepath and -logfile     options when starting Xorg. X server allows     unprivileged users with the ability to log in to the     system via physical console to escalate their     privileges and run arbitrary code under root     privileges.(CVE-2018-14665)

  - In the X.Org X server before 2017-06-19, a user     authenticated to an X Session could crash or execute     code in the context of the X Server by exploiting a     stack overflow in the endianness conversion of X     Events.(CVE-2017-10971)

  - Uninitialized data in endianness conversion in the     XEvent handling of the X.Org X Server before 2017-06-19     allowed authenticated malicious users to access     potentially privileged data from the X     server.(CVE-2017-10972)

  - xorg-x11-server before 1.19.5 was missing extra length     validation in ProcEstablishConnection function allowing     malicious X client to cause X server to crash or     possibly execute arbitrary code.(CVE-2017-12176)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for xorg-x11-server fixes several issues. These security issues were fixed :

  - CVE-2017-13721: Missing validation of shmseg resource id     in Xext/XShm could lead to shared memory segments of     other users beeing freed (bnc#1052984)

  - CVE-2017-13723: A local denial of service via unusual     characters in XkbAtomText and XkbStringText was fixed     (bnc#1051150)

  -     CVE-2017-12184,CVE-2017-12185,CVE-2017-12186,CVE-2017-12     187: Fixed unvalidated lengths in multiple extensions     (bsc#1063034)

  - CVE-2017-12183: Fixed some unvalidated lengths in the     XFIXES extension. (bsc#1063035)

  - CVE-2017-12180,CVE-2017-12181,CVE-2017-12182: Fixed     various unvalidated lengths in the     XFree86-VidMode/XFree86-DGA/XFree86-DRI extensions     (bsc#1063037)

  - CVE-2017-12179: Fixed an integer overflow and     unvalidated length in (S)ProcXIBarrierReleasePointer in     Xi (bsc#1063038)

  - CVE-2017-12178: Fixed a wrong extra length check in     ProcXIChangeHierarchy in Xi (bsc#1063039)

  - CVE-2017-12177: Fixed an unvalidated variable-length     request in ProcDbeGetVisualInfo (bsc#1063040)

  - CVE-2017-12176: Fixed an unvalidated extra length in     ProcEstablishConnection (bsc#1063041)

The update package also includes non-security fixes. See advisory for details.

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote host is affected by the vulnerability described in GLSA-201710-30 (X.Org Server: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in X.Org Server. Please       review the referenced CVE identifiers for details.
  Impact :

    A local attacker could cause a global buffer overflow or a Denial of       Service condition.
  Workaround :

    There is no known workaround at this time

Several vulnerabilities have been discovered in the X.Org X server. An attacker who's able to connect to an X server could cause a denial of service or potentially the execution of arbitrary code.

Michal Srb discovered that the X.Org X server incorrectly handled shared memory segments. An attacker able to connect to an X server, either locally or remotely, could use this issue to crash the server, or possibly replace shared memory segments of other X clients in the same session. (CVE-2017-13721)

Michal Srb discovered that the X.Org X server incorrectly handled XKB buffers. An attacker able to connect to an X server, either locally or remotely, could use this issue to crash the server, or possibly execute arbitrary code. (CVE-2017-13723).

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.

Alan Coopersmith reports :

X.Org thanks Michal Srb of SuSE for finding these issues and bringing them to our attention, Julien Cristau of Debian for getting the fixes integrated, and Adam Jackson of Red Hat for publishing the release.

New xorg-server packages are available for Slackware 14.0, 14.1, 14.2, and -current to fix security issues.

ID	Name	Product	Family	Severity
132218	EulerOS 2.0 SP3 : xorg-x11-server (EulerOS-SA-2019-2683)	Nessus	Huawei Local Security Checks	critical
131913	EulerOS 2.0 SP2 : xorg-x11-server (EulerOS-SA-2019-2421)	Nessus	Huawei Local Security Checks	critical
104776	SUSE SLED12 / SLES12 Security Update : xorg-x11-server (SUSE-SU-2017:3047-1)	Nessus	SuSE Local Security Checks	critical
104231	GLSA-201710-30 : X.Org Server: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
103882	Debian DSA-4000-1 : xorg-server - security update	Nessus	Debian Local Security Checks	critical
103834	Ubuntu 14.04 LTS / 16.04 LTS : X.Org X server vulnerabilities (USN-3453-1)	Nessus	Ubuntu Local Security Checks	high
103741	FreeBSD : xorg-server -- multiple vulnabilities (4f8ffb9c-f388-4fbd-b90f-b3131559d888)	Nessus	FreeBSD Local Security Checks	high
103705	Slackware 14.0 / 14.1 / 14.2 / current : xorg-server (SSA:2017-279-03)	Nessus	Slackware Local Security Checks	high

Detections

Analytics

CVE-2017-13721

medium

Tenable Plugins

critical

critical

critical

high

critical

high

high

high