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CVE-2018-6789

Known Exploited (CISA KEV)CRITICAL
9.8
CVSS Severity Score
EPSS Score39.9630%
EPSS Percentile85.16th
PublishedFeb 8, 2018
Last ModifiedNov 7, 2025

Vulnerability Description

An issue was discovered in the base64d function in the SMTP listener in Exim before 4.90.1. By sending a handcrafted message, a buffer overflow may happen. This can be used to execute code remotely.

Affected Platforms (CPE)

📦
Exim

Exim

< 4.90.1
💻
Debian

Debian Linux

= 7.0
💻
Debian

Debian Linux

= 8.0
💻
Debian

Debian Linux

= 9.0
💻
Canonical

Ubuntu Linux

= 14.04
💻
Canonical

Ubuntu Linux

= 16.04
💻
Canonical

Ubuntu Linux

= 17.10

References & Advisories

🔗 http://openwall.com/lists/oss-security/2018/02/10/2
🔗 http://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.html
🔗 http://www.openwall.com/lists/oss-security/2018/02/07/2
🔗 http://www.securityfocus.com/bid/103049
🔗 http://www.securitytracker.com/id/1040461
🔗 https://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/
🔗 https://exim.org/static/doc/security/CVE-2018-6789.txt
🔗 https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1

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