VULNERABILITY INTELLIGENCE
CVE-2023-51766
CVSS score5.3 MEDIUM
EPSS probability1.10%
CISA KEVNot currently listed
Published2023-12-24
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Description
Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations. Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because Exim supports <LF>.<CR><LF> but some other popular e-mail servers do not.
Weakness classification
- nvd@nist.gov: CWE-345
Primary references
- cve@mitre.org — Mailing List, Third Party Advisory
- cve@mitre.org — Mailing List, Third Party Advisory
- cve@mitre.org — Mailing List, Mitigation, Third Party Advisory
- cve@mitre.org — Mailing List, Third Party Advisory
- cve@mitre.org — Mailing List, Third Party Advisory
- cve@mitre.org — Mailing List, Third Party Advisory
- cve@mitre.org — Issue Tracking, Vendor Advisory
- cve@mitre.org — Issue Tracking, Third Party Advisory
- cve@mitre.org — Broken Link
- cve@mitre.org — Technical Description
- cve@mitre.org — Patch
- cve@mitre.org — Patch