SB2026072371 - Multiple vulnerabilities in Exim

Description

This security bulletin contains information about 2 vulnerabilities.

1) Path traversal (CVE-ID: N/A)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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

The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to path traversal in command-line queue-name handling when processing command-line arguments intended for transferring queue-name through an Exim execution chain. A local user can supply crafted command-line arguments to escalate privileges.

To reach the vulnerable code, command-line access on the system is required.

2) Improper privilege management (CVE-ID: N/A)

CWE-ID: CWE-269 - Improper Privilege Management

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

The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to improper access control in .forward string expansion in pipe transports when processing a .forward file with string expansion under force_command. A local user can place crafted string expansion content in a .forward file to escalate privileges.

Exploitation requires a redirect router implementing .forward facilities for local users, a pipe transport accessible by that router, the pipe transport to have the force_command option set, and the pipe transport to be configured to run as a privileged user.

Remediation

Install update from vendor's website.

References

• https://www.exim.org/static/doc/security/EXIM-Security-2026-06-22.1/EXIM-Security-2026-06-22.1.txt
• https://code.exim.org/exim/exim
• https://www.exim.org/static/doc/security/EXIM-Security-2026-06-22.3/EXIM-Security-2026-06-22.3.txt