CVE-2024-27938

CVE-2024-27938 is a medium-severity vulnerability in Postalserver Postal with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-116.

Key facts

Description

Postal is an open source SMTP server. Postal versions less than 3.0.0 are vulnerable to SMTP Smuggling attacks which may allow incoming e-mails to be spoofed. This, in conjunction with a cooperative outgoing SMTP service, would allow for an incoming e-mail to be received by Postal addressed from a server that a user has 'authorised' to send mail on their behalf but were not the genuine author of the e-mail. Postal is not affected for sending outgoing e-mails as email is re-encoded with `<CR><LF>` line endings when transmitted over SMTP. This issue has been addressed and users should upgrade to Postal v3.0.0 or higher. Once upgraded, Postal will only accept End of DATA sequences which are explicitly `<CR><LF>.<CR><LF>`. If a non-compliant sequence is detected it will be logged to the SMTP server log. There are no workarounds for this issue.

Frequently asked questions

What is CVE-2024-27938?
Postal is an open source SMTP server. Postal versions less than 3.0.0 are vulnerable to SMTP Smuggling attacks which may allow incoming e-mails to be spoofed. This, in conjunction with a cooperative outgoing SMTP service, would allow for an incoming e-mail to be received by Postal addressed from a server that a user has 'authorised' to send mail on their behalf but were not the genuine author of the e-mail. Postal is not affected for sending outgoing e-mails as email is re-encoded with `<CR><LF>` line endings when transmitted over SMTP. This issue has been addressed and users should upgrade to Postal v3.0.0 or higher. Once upgraded, Postal will only accept End of DATA sequences which are explicitly `<CR><LF>.<CR><LF>`. If a non-compliant sequence is detected it will be logged to the SMTP server log. There are no workarounds for this issue.
How severe is CVE-2024-27938?
CVE-2024-27938 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2024-27938 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-27938?
CVE-2024-27938 affects Postalserver Postal. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-27938?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-27938 have an EU (EUVD) identifier?
Yes. CVE-2024-27938 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-25112.
When was CVE-2024-27938 published?
CVE-2024-27938 was published on 2024-03-11 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Postalserver Postal

All CVEs affecting Postalserver Postal →

Other CWE-116 vulnerabilities

Browse all CWE-116 vulnerabilities →