Detections
Analytics
Amazon Linux 2 : tigervnc (ALAS-2024-2510)
high Nessus Plugin ID 193523
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Synopsis
The remote Amazon Linux 2 host is missing a security update.Description
The version of tigervnc installed on the remote host is prior to 1.8.0-24. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2024-2510 advisory.A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIGetSelectedEvents() function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker's inability to control the specific memory copied into the replies, the small length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds reads. (CVE-2024-31080)
A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIPassiveGrabDevice() function. This issue occurs when byte-swapped length values are used in replies, potentially leading to memory leakage and segmentation faults, particularly when triggered by a client with a different endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory values and then transmit them back to the client until encountering an unmapped page, resulting in a crash. Despite the attacker's inability to control the specific memory copied into the replies, the small length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds reads. (CVE-2024-31081)
The ProcRenderAddGlyphs() function calls the AllocateGlyph() function to store new glyphs sent by the client to the X server. AllocateGlyph() would return a new glyph with refcount=0 and a re-used glyph would end up not changing the refcount at all. The resulting glyph_new array would thus have multiple entries pointing to the same non-refcounted glyphs.
ProcRenderAddGlyphs() may free a glyph, resulting in a use-after-free when the same glyph pointer is then later used. (CVE-2024-31083)
Tenable has extracted the preceding description block directly from the tested product security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Run 'yum update tigervnc' to update your system.See Also
https://alas.aws.amazon.com/AL2/ALAS-2024-2510.html
https://alas.aws.amazon.com/cve/html/CVE-2024-31080.html
https://alas.aws.amazon.com/cve/html/CVE-2024-31081.html
Plugin Details
Severity: High
ID: 193523
File Name: al2_ALAS-2024-2510.nasl
Version: 1.1
Type: local
Agent: unix
Published: 4/18/2024
Updated: 12/11/2024
Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 6.7
CVSS v2
Risk Factor: High
Base Score: 8
Temporal Score: 5.9
Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:C
CVSS Score Source: CVE-2024-31081
CVSS v3
Risk Factor: High
Base Score: 7.8
Temporal Score: 6.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
CVSS Score Source: CVE-2024-31083
Vulnerability Information
CPE: p-cpe:/a:amazon:linux:tigervnc-icons, p-cpe:/a:amazon:linux:tigervnc-server-module, p-cpe:/a:amazon:linux:tigervnc-debuginfo, p-cpe:/a:amazon:linux:tigervnc, p-cpe:/a:amazon:linux:tigervnc-server-applet, p-cpe:/a:amazon:linux:tigervnc-server-minimal, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:tigervnc-server, p-cpe:/a:amazon:linux:tigervnc-license
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 4/11/2024
Vulnerability Publication Date: 4/4/2024