CVE-2020-28013 Memory corruption in n/a

High 7.8 Published 6 May 2021 Updated 4 Aug 2024

A heap-based buffer overflow in Exim allows local attackers to escalate privileges to root via command line arguments.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2020-28013?

CVE-2020-28013 is a high-severity memory corruption vulnerability in Exim Exim, published on 6 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Exim 4 before 4.94.2 allows Heap-based Buffer Overflow because it mishandles "-F '.('" on the command line, and thus may allow privilege escalation from any user to root. This occurs because of the interpretation of negative sizes in strncpy.

Weakness: CWE-787

Which versions are affected by CVE-2020-28013?

It affects 1 product.

Products include Exim Exim.

How do I fix CVE-2020-28013?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2020-28013 being exploited?

There is no known exploitation of CVE-2020-28013 in the wild and no public exploit code.

All Exim Exim vulnerabilities

Sources

Also known as CLEANSTART-2025-UJ87272, DEBIAN-CVE-2020-28013, GHSA-vfqg-p6x8-w5f4, UBUNTU-CVE-2020-28013.