CVE-2020-28016 Memory corruption in n/a
An off-by-two out-of-bounds write in Exim's parse_fix_phrase function allows attackers to potentially execute arbitrary code or cause a denial of service.
- 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-2020-28016?
CVE-2020-28016 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 an off-by-two Out-of-bounds Write because "-F ''" is mishandled by parse_fix_phrase.
Weakness: CWE-787
Which versions are affected by CVE-2020-28016?
It affects 1 product.
Products include Exim Exim.
How do I fix CVE-2020-28016?
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-2020-28016 being exploited?
There is no known exploitation of CVE-2020-28016 in the wild and no public exploit code.
Other vulnerabilities in Exim Exim
Sources
Also known as CLEANSTART-2025-PY86183, DEBIAN-CVE-2020-28016, GHSA-ggp5-gp7q-6r3v.