How severe is CVE-2020-28016?

CVE-2020-28016 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-28016 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-28016?

CVE-2020-28016 affects Exim. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-28016?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-28016 published?

CVE-2020-28016 was published on 2021-05-06 and last updated on 2026-06-17.

CVE-2020-28016

CVE-2020-28016 is a high-severity vulnerability in Exim with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Exim
Published: 2021-05-06
Last modified: 2026-06-17

Description

Exim 4 before 4.94.2 allows an off-by-two Out-of-bounds Write because "-F ''" is mishandled by parse_fix_phrase.

Frequently asked questions

What is CVE-2020-28016?: Exim 4 before 4.94.2 allows an off-by-two Out-of-bounds Write because "-F ''" is mishandled by parse_fix_phrase.
How severe is CVE-2020-28016?: CVE-2020-28016 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-28016 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-28016?: CVE-2020-28016 affects Exim. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-28016?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-28016 published?: CVE-2020-28016 was published on 2021-05-06 and last updated on 2026-06-17.

References

https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28016-PFPZA.txt

Affected products (1)

cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

76.12.128.249 (ipv4-addr)
50.116.72.139 (ipv4-addr)
166.62.41.190 (ipv4-addr)
132.148.155.138 (ipv4-addr)
50.62.22.47 (ipv4-addr)
31.131.22.122 (ipv4-addr)
193.68.57.43 (ipv4-addr)
192.169.201.223 (ipv4-addr)