Medium: libX11

Issue Overview:

An off-by-one error has been discovered in libX11 in functions XGetFontPath(), XListExtensions(), and XListFonts(). An attacker who can either configure a malicious X server or modify the data coming from one could use this flaw to make the program crash or have other unspecified effects, caused by the memory corruption. (CVE-2018-14599)

It was discovered that libX11 does not properly validate input coming from the server, causing XListExtensions() and XGetFontPath() functions to produce an invalid list of elements that in turn make XFreeExtensionsList() and XFreeFontPath() access invalid memory. An attacker who can either configure a malicious X server or modify the data coming from one, could use this flaw to crash the application using libX11, resulting in a denial of service. (CVE-2018-14598)

Affected Packages:

libX11

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update libX11 to update your system.

New Packages:

aarch64:  
    libX11-1.6.5-2.amzn2.0.2.aarch64  
    libX11-devel-1.6.5-2.amzn2.0.2.aarch64  
    libX11-debuginfo-1.6.5-2.amzn2.0.2.aarch64  
  
i686:  
    libX11-1.6.5-2.amzn2.0.2.i686  
    libX11-devel-1.6.5-2.amzn2.0.2.i686  
    libX11-debuginfo-1.6.5-2.amzn2.0.2.i686  
  
noarch:  
    libX11-common-1.6.5-2.amzn2.0.2.noarch  
  
src:  
    libX11-1.6.5-2.amzn2.0.2.src  
  
x86_64:  
    libX11-1.6.5-2.amzn2.0.2.x86_64  
    libX11-devel-1.6.5-2.amzn2.0.2.x86_64  
    libX11-debuginfo-1.6.5-2.amzn2.0.2.x86_64  

Additional References

Red Hat: CVE-2018-14598, CVE-2018-14599

Mitre: CVE-2018-14598, CVE-2018-14599