Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2018-6789

CVE-2018-6789CRITICAL

n/a n/a — Exim Exim

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  H  H  H    9.8   .8214   99.6   YES

AFFECTED
  Product  Versions  Fixed
  n/a      n/a –     —

TIMELINE
  Feb 6   Reserved by mitre
  Feb 8   Published (CNA: mitre)
  Nov 3   Added to CISA KEV, remediation due 2022-05-03

CWE-120 · CNA: mitre · CVSS v3.1 · 14 references · KEV due May 3, 2022

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
February 6, 2018	Reserved	Reserved by mitre
February 8, 2018	Published	Published (CNA: mitre)
November 3, 2021	KEV ADDED	Added to CISA KEV, remediation due 2022-05-03

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	n/a	—	n/a	—

Weaknesses

CWE-120

References (14)

http://openwall.com/lists/oss-security/2018/02/10/2 [x_refsource_CONFIRM]
http://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.html [x_refsource_MISC]
http://www.openwall.com/lists/oss-security/2018/02/07/2 [mailing-list, x_refsource_MLIST]
http://www.securityfocus.com/bid/103049 [vdb-entry, x_refsource_BID]
http://www.securitytracker.com/id/1040461 [vdb-entry, x_refsource_SECTRACK]
https://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/ [x_refsource_MISC]
https://exim.org/static/doc/security/CVE-2018-6789.txt [x_refsource_CONFIRM]
https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1 [x_refsource_CONFIRM]
https://lists.debian.org/debian-lts-announce/2018/02/msg00009.html [mailing-list, x_refsource_MLIST]
https://usn.ubuntu.com/3565-1/ [vendor-advisory, x_refsource_UBUNTU]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-6789 [government-resource]
https://www.debian.org/security/2018/dsa-4110 [vendor-advisory, x_refsource_DEBIAN]
https://www.exploit-db.com/exploits/44571/ [exploit, x_refsource_EXPLOIT-DB]
https://www.exploit-db.com/exploits/45671/ [exploit, x_refsource_EXPLOIT-DB]

Authoritative record: CVE-2018-6789 at cve.org

Weaknesses: CWE-120

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2018-6789 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.