What’s Vulnerable › Vulnerabilities

CVE-2020-28013

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-05-06 · updated 2026-06-17
• Weakness: CWE-787

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.

Affected products

• Exim: from 4.00 before 4.94.2 — fixed in 4.94.2

How to fix

Upgrade to a fixed version: Exim 4.94.2. Check the vendor advisory for mitigations.

References

• https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28013-PFPSN.txt
• https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28013-PFPSN.txt

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