Medium severity · published Dec 24, 2023
CVE-2023-51766
Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations
5.3
CVSS
1.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.1% · higher than 66% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
10.0 · source: NVD
EX
Exim · Exim
before 4.97.1 · source: NVD
EP
Extra Packages For Enterprise Linux · Fedoraproject
7.0; 8.0; 9.0 · source: NVD
FE
Fedora · Fedoraproject
38; 39 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-51766
CVE.org
https://www.cve.org/CVERecord?id=CVE-2023-51766
Mailing List
http://www.openwall.com/lists/oss-security/2023/12/24/1
Mailing List
http://www.openwall.com/lists/oss-security/2023/12/25/1
Mailing List
http://www.openwall.com/lists/oss-security/2023/12/29/2
Mailing List
http://www.openwall.com/lists/oss-security/2024/01/01/1
Mailing List
http://www.openwall.com/lists/oss-security/2024/01/01/2
Mailing List
http://www.openwall.com/lists/oss-security/2024/01/01/3
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