Remote Code Execution (RCE) Affecting exim/exim package, versions [,4.96.1)


Severity

Recommended
0.0
critical
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.08% (36th percentile)

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  • Snyk IDSNYK-UNMANAGED-EXIMEXIM-5925628
  • published29 Sept 2023
  • disclosed28 Sept 2023
  • creditZero Day Initiative

Introduced: 28 Sep 2023

CVE-2023-42115  (opens in a new tab)
CWE-94  (opens in a new tab)

How to fix?

Upgrade exim/exim to version 4.96.1 or higher.

Overview

Affected versions of this package are vulnerable to Remote Code Execution (RCE). The specific flaw exists within the SMTP service, which listens on TCP port 25 by default. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of a buffer. An attacker can leverage this vulnerability to execute code in the context of the service account.

Note:

Authentication is not required to exploit this vulnerability.

Mitigation:

Users can run exim4 -bP configure_file command to determine whether the “External” authentication is active. If the settings include driver = external, users should consider switching to a different authentication method or limiting remote access to the server altogether.

CVSS Scores

version 3.1