CVE-2023-51765
Published: 24 December 2023
Summary
CVE-2023-51765 is a medium-severity Insufficient Verification of Data Authenticity (CWE-345) vulnerability in Redhat Enterprise Linux. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Email Spoofing (T1684.002); ranked in the top 24.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-56454
Vulnerability details
sendmail through 8.17.2 allows SMTP smuggling in certain 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 sendmail supports <LF>.<CR><LF>…
more
but some other popular e-mail servers do not. This is resolved in 8.18 and later versions with 'o' in srv_features.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CVE-2023-51765 enables SMTP smuggling in sendmail, allowing remote attackers to inject emails with spoofed MAIL FROM addresses and bypass SPF protections, directly facilitating Email Spoofing (T1672).
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Directly requires independent verification of matching output before adverse decisions, mitigating insufficient authenticity checks on data from external sources.
Use of approved PKI certificates provides verifiable data authenticity and origin for communications and artifacts.
Mandates provision of authenticity and integrity artifacts that enable verification of name/address resolution data.
Requires explicit verification of data authenticity from authoritative sources, preventing acceptance of unauthenticated resolution responses.
Control requires verification of data authenticity/integrity (e.g., checksums) after aggregation/packing, directly reducing exploitation of insufficient verification before transmission.
Time synchronization supports reliable freshness verification when checking data authenticity across systems or components.
Mandates verification of data authenticity for software, firmware, and information.
Provenance documentation and monitoring directly enables verification of authenticity for components and data throughout their history.