CVE-2018-6789

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2021-11-03. Federal remediation due 2022-05-03.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

82.14% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 99.6% of scored records. A rank, not a probability.

NVD base score

9.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Critical. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2018-02-08 23:00Z8 YR AGO

Last updated

2025-10-21 23:45Z10 MO AGO

Reserved

2018-02-06

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weaknesses

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')Base

Data version

5.1

Document digest

bf7469a38508dc6bdf0e0a1c9da031144b719ad319d2031a8c1daffc9dda8146

• exim.orghttps://exim.org/static/doc/security/CVE-2018-6789.txtx_refsource_CONFIRM
• www.openwall.com[oss-security] 20180207 CVE-2018-6789 Exim 4.90 and earlier: buffer overflowhttp://www.openwall.com/lists/oss-security/2018/02/07/2mailing-listx_refsource_MLIST
• usn.ubuntu.comUSN-3565-1https://usn.ubuntu.com/3565-1/vendor-advisoryx_refsource_UBUNTU
• openwall.comhttp://openwall.com/lists/oss-security/2018/02/10/2x_refsource_CONFIRM
• www.securitytracker.com1040461http://www.securitytracker.com/id/1040461vdb-entryx_refsource_SECTRACK
• www.debian.orgDSA-4110https://www.debian.org/security/2018/dsa-4110vendor-advisoryx_refsource_DEBIAN
• www.exploit-db.com44571https://www.exploit-db.com/exploits/44571/exploitx_refsource_EXPLOIT-DB
• lists.debian.org[debian-lts-announce] 20180210 [SECURITY] [DLA 1274-1] exim4 security updatehttps://lists.debian.org/debian-lts-announce/2018/02/msg00009.htmlmailing-listx_refsource_MLIST
• git.exim.orghttps://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1x_refsource_CONFIRM
• devco.rehttps://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/x_refsource_MISC
• www.securityfocus.com103049http://www.securityfocus.com/bid/103049vdb-entryx_refsource_BID
• www.exploit-db.com45671https://www.exploit-db.com/exploits/45671/exploitx_refsource_EXPLOIT-DB
• packetstormsecurity.comhttp://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.htmlx_refsource_MISC
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-6789government-resource