SB20260629118 - Ubuntu update for xrdp



SB20260629118 - Ubuntu update for xrdp

Published: June 29, 2026

Security Bulletin ID SB20260629118
CSH Severity
High
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 25% Medium 50% Low 25%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Stack-based buffer overflow (CVE-ID: CVE-2025-68670)

CWE-ID: CWE-121 - Stack-based buffer overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error. A remote unauthenticated attacker can trigger stack-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


2) Improper Restriction of Excessive Authentication Attempts (CVE-ID: CVE-2024-39917)

CWE-ID: CWE-307 - Improper Restriction of Excessive Authentication Attempts

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to improper restriction of excessive authentication attempts within the MaxLoginRetry parameter in /etc/xrdp/sesman.ini. A remote attacker can make an infinite number of login attempts.


3) Out-of-bounds read (CVE-ID: CVE-2023-42822)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote user to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition in xrdp_painter.c when accessing the font glyphs. A remote user can trigger an out-of-bounds read error and read contents of memory on the system.

Successful exploitation of the vulnerability may lead to system compromise.


4) Security features bypass (CVE-ID: CVE-2023-40184)

CWE-ID: CWE-254 - Security Features

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to bypass implemented security restrictions.

The vulnerability exists due to improper handling of session restrictions inside the xrdp-sesman. A remote user can bypass session restrictions, such as max concurrent sessions per user enforced by PAM.


Remediation

Install update from vendor's website.