X.org X11 Server up to 1.20.8 X Input Extension Protocol Decoder integer overflow

Summaryinfo

A vulnerability classified as critical was found in X.org X11 Server up to 1.20.8. This vulnerability affects unknown code of the component X Input Extension Protocol Decoder. Such manipulation leads to integer overflow. This vulnerability is uniquely identified as CVE-2020-14346. Local access is required to approach this attack. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in X.org X11 Server up to 1.20.8 (Windowing System Software). It has been rated as critical. Affected by this issue is an unknown function of the component X Input Extension Protocol Decoder. The manipulation with an unknown input leads to a integer overflow vulnerability. Using CWE to declare the problem leads to CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A flaw was found in xorg-x11-server before 1.20.9. An integer underflow in the X input extension protocol decoding in the X server may lead to arbitrary access of memory contents. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

The weakness was disclosed 09/15/2020 as Bug 1862246 as not defined bug report (Bugzilla). The advisory is shared for download at bugzilla.redhat.com. This vulnerability is handled as CVE-2020-14346 since 06/17/2020. The attack needs to be approached locally. The successful exploitation requires a simple authentication. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 236625 (Alibaba Cloud Linux 3 : 0114: userspace graphics, xorg-x11, and mesa (ALINUX3-SA-2022:0114)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.20.9 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (236625). The entries VDB-161254, VDB-161253 and VDB-161251 are pretty similar. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Windowing System Software

Vendor

• X.org

Name

• X11 Server

Version

• 1.20.0
• 1.20.1
• 1.20.2
• 1.20.3
• 1.20.4
• 1.20.5
• 1.20.6
• 1.20.7
• 1.20.8

License

• open-source

Website

• Vendor: https://www.x.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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