CVE-2023-51766
MEDIUMCVSS v3
5.3
MEDIUM
EPSS Score
1.1%
exploit probability
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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.
Technical Details
- Published
- 12/24/2023
Frequently Asked Questions
What is CVE-2023-51766?
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.
Is CVE-2023-51766 actively exploited?
Active exploitation of CVE-2023-51766 has not been confirmed. The EPSS score is 1.1%, indicating the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2023-51766?
CVE-2023-51766 has a CVSS v3 base score of 5.3 (MEDIUM severity).
Is CVE-2023-51766 affecting your environment?
Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.