SB2021031560 - Ubuntu update for xrdp



SB2021031560 - Ubuntu update for xrdp

Published: March 15, 2021 Updated: October 31, 2026

Security Bulletin ID SB2021031560
CSH Severity
High
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

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

Description

This security bulletin contains information about 2 vulnerabilities.


1) Buffer overflow (CVE-ID: CVE-2017-16927)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

The scp_v0s_accept function in sesman/libscp/libscp_v0.c in the session manager in xrdp through 0.9.4 uses an untrusted integer as a write length, which allows local users to cause a denial of service (buffer overflow and application crash) or possibly have unspecified other impact via a crafted input stream.


2) Improper Authentication (CVE-ID: CVE-2017-6967)

CWE-ID: CWE-287 - Improper Authentication

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

xrdp 0.9.1 calls the PAM function auth_start_session() in an incorrect location, leading to PAM session modules not being properly initialized, with a potential consequence of incorrect configurations or elevation of privileges, aka a pam_limits.so bypass.


Remediation

Install update from vendor's website.