VulnerabilityAnalyzed
CVE-2018-6789
Exim Buffer Overflow Vulnerability
KEVCRITICAL 9.8EPSS 82.1%
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 3 May 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 82.14% probability · 100th percentile
- CISA KEV
- Listed 3 November 2021 · due 3 May 2022 · used in ransomware campaigns
- Weakness
- CWE-120
- Affected
- exim/exim · debian/debian linux · canonical/ubuntu linux
- Source
- cve@mitre.org
CISA notes
Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2018-6789
References
- http://openwall.com/lists/oss-security/2018/02/10/2Mailing List, Third Party Advisory
- http://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.htmlExploit, Third Party Advisory, VDB Entry
- http://www.openwall.com/lists/oss-security/2018/02/07/2Mailing List, Third Party Advisory
- http://www.securityfocus.com/bid/103049Broken Link, Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1040461Broken Link, Third Party Advisory, VDB Entry
- https://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/Exploit, Third Party Advisory
- https://exim.org/static/doc/security/CVE-2018-6789.txtVendor Advisory
- https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1Patch
- https://lists.debian.org/debian-lts-announce/2018/02/msg00009.htmlMailing List, Third Party Advisory
- https://usn.ubuntu.com/3565-1/Third Party Advisory
- https://www.debian.org/security/2018/dsa-4110Mailing List, Third Party Advisory
- https://www.exploit-db.com/exploits/44571/Exploit, Third Party Advisory, VDB Entry
- https://www.exploit-db.com/exploits/45671/Exploit, Third Party Advisory, VDB Entry
- http://openwall.com/lists/oss-security/2018/02/10/2Mailing List, Third Party Advisory
- http://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.htmlExploit, Third Party Advisory, VDB Entry
- http://www.openwall.com/lists/oss-security/2018/02/07/2Mailing List, Third Party Advisory
- http://www.securityfocus.com/bid/103049Broken Link, Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1040461Broken Link, Third Party Advisory, VDB Entry
- https://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/Exploit, Third Party Advisory
- https://exim.org/static/doc/security/CVE-2018-6789.txtVendor Advisory
- https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1Patch
- https://lists.debian.org/debian-lts-announce/2018/02/msg00009.htmlMailing List, Third Party Advisory
- https://usn.ubuntu.com/3565-1/Third Party Advisory
- https://www.debian.org/security/2018/dsa-4110Mailing List, Third Party Advisory
- https://www.exploit-db.com/exploits/44571/Exploit, Third Party Advisory, VDB Entry
- https://www.exploit-db.com/exploits/45671/Exploit, Third Party Advisory, VDB Entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-6789US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.