PT-2020-5810 · Libvncserver+1 · X11Vnc+1

Guenal Davalan · Published 2020-10-18 · Updated 2024-06-15 · CVE-2020-29074

Positive Technologies (AI Summary)

CVSS v3.1

8.8

High

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions: x11vnc version 0.9.16

Description: The issue is related to the scan.c component of the X11vnc VNC server, which lacks an authorization mechanism. This allows a remote attacker to access confidential data, compromise its integrity, and cause a denial of service. The vulnerability is due to the use of IPC CREAT|0777 in shmget calls, which permits access by actors other than the current user.

Recommendations: For x11vnc version 0.9.16, consider restricting access to the vulnerable scan.c component until a patch is available. As a temporary workaround, restrict the use of the shmget function with IPC CREAT|0777 permissions to minimize the risk of exploitation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Missing Authorization

Incorrect Permission

Weakness Enumeration

CWE-862

CWE-732

Related Identifiers

ALT-PU-2021-1102

ALT-PU-2021-1142

ALT-PU-2021-2155

BDU:2021-01776

CVE-2020-29074

DLA-2490-1

DSA-4799-1

MGASA-2020-0454

OPENSUSE-SU-2024:11496-1

Affected Products

Alt Linux

X11Vnc

References · 33

• https://github.com/LibVNC/x11vnc/commit/69eeb9f7baa14ca03b16c9de821f9876def7a36a · Patch
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/PZL6NQTNK5PT63D2JX5YVV5OLUL76S5C · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2020-29074 · Security Note
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/MHVXHZE3YIP4RTWGQ24IDBSW44XPRDOC · Vendor Advisory
• https://debian.org/security/2020/dsa-4799 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2020-29074 · Security Note
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H2FLWSVH32O6JXLRQBYDQLP7XRSTLUPQ · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MHVXHZE3YIP4RTWGQ24IDBSW44XPRDOC · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PZL6NQTNK5PT63D2JX5YVV5OLUL76S5C · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-01776 · Security Note
• https://osv.dev/vulnerability/MGASA-2020-0454 · Vendor Advisory
• https://osv.dev/vulnerability/DSA-4799-1 · Vendor Advisory
• https://advisories.mageia.org/MGASA-2020-0454.html · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2020-29074 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/[e-mail]/message/H2FLWSVH32O6JXLRQBYDQLP7XRSTLUPQ · Vendor Advisory