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.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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)

Note that Nessus relies on the presence of the package as reported by the vendor.

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.

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.

For Debian 7 'Wheezy', these problems have been fixed in version 2:1.12.4-6+deb7u8.

We recommend that you upgrade your xorg-server packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA 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

The remote Ubuntu 14.04 LTS / 16.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-3362-1 advisory.

    It was discovered that the X.Org X server incorrectly handled endianness conversion of certain X events.
    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 as an administrator. (CVE-2017-10971)

    It was discovered that the X.Org X server incorrectly handled endianness conversion of certain X events.
    An attacker able to connect to an X server, either locally or remotely, could use this issue to possibly     obtain sensitive information. (CVE-2017-10972)

    Eric Sesterhenn discovered that the X.Org X server incorrectly compared MIT cookies. An attacker could     possibly use this issue to perform a timing attack and recover the MIT cookie. (CVE-2017-2624)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

This update for xorg-x11-server fixes the following issues: Security issues :

  - CVE-2017-2624: Prevent timing attack against MIT cookie.
    (bsc#1025029, CVE-2017-2624) Non security issues :

  - Use arc4random to generate cookies. (bsc#1025084)

  - XDrawArc performance improvement (bsc#1019649)

  - Fix byte swapping for gradeint stops (bsc#981044).

  - Remove unused function with use-after-free issue.
    (bsc#1025035)

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.

This update for xorg-x11-server provides the following fixes :

  - Remove unused function with use-after-free issue.
    (bsc#1025035)

  - Use arc4random to generate cookies. (bsc#1025084)

  - Prevent timing attack against MIT cookie. (bsc#1025029,     CVE-2017-2624)

  - XDrawArc performance improvement. (bsc#1019649)

  - Re-enable indirect GLX by default. (bsc#1039042)

  - Add IndirectGLX ServerFlags option which allows users to     enable or disable indirect GLX. (bsc#1032509)

  - Fix dashing in GLAMOR. (bsc#1021803)

  - Fix X server crash on drawing dashed lines.
    (bsc#1025985)

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.

This update for xorg-x11-server fixes the following security issues :

  - CVE-2017-2624: Prevent timing attack against MIT cookie.
    (boo#1025029)

  - Use arc4random to generate cookies with more randomness.
    (boo#1025084)

  - Remove unused function with use-after-free issue.
    (boo#1025035)

The remote host is affected by the vulnerability described in GLSA-201704-03 (X.Org: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in X.Org server and       libraries. Please review the CVE identifiers referenced below for       details.
  Impact :

    A local or remote users can utilize the vulnerabilities to attach to the       X.Org session as a user and execute arbitrary code.
  Workaround :

    There is no known workaround at this time.

ID	Name	Product	Family	Severity
220941	Linux Distros Unpatched Vulnerability : CVE-2017-2624	Nessus	Misc.	high
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
104745	Debian DLA-1186-1 : xorg-server security update	Nessus	Debian Local Security Checks	critical
104231	GLSA-201710-30 : X.Org Server: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
101949	Ubuntu 14.04 LTS / 16.04 LTS : X.Org X server vulnerabilities (USN-3362-1)	Nessus	Ubuntu Local Security Checks	high
101201	SUSE SLES11 Security Update : xorg-x11-server (SUSE-SU-2017:1741-1)	Nessus	SuSE Local Security Checks	high
101059	SUSE SLED12 / SLES12 Security Update : xorg-x11-server (SUSE-SU-2017:1675-1)	Nessus	SuSE Local Security Checks	high
100883	openSUSE Security Update : xorg-x11-server (openSUSE-2017-710)	Nessus	SuSE Local Security Checks	high
99276	GLSA-201704-03 : X.Org: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	critical

Detections

Analytics

CVE-2017-2624

high

Tenable Plugins

high

critical

critical

critical

high

high

high

high

high

critical