What’s Vulnerable › Vulnerabilities

CVE-2020-28017

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 36.9% 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-190

Description

Exim 4 before 4.94.2 allows Integer Overflow to Buffer Overflow in receive_add_recipient via an e-mail message with fifty million recipients. NOTE: remote exploitation may be difficult because of resource consumption.

Affected products

• Exim: before 4.94.1 — fixed in 4.94.1

How to fix

Upgrade to a fixed version: Exim 4.94.1. Check the vendor advisory for mitigations.

References

• https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28017-RCPTL.txt
• https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28017-RCPTL.txt

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