CVE-2024-39929: exim Improper Encoding

Description

Exim through 4.97.1 misparses a multiline RFC 2231 header filename, and thus remote attackers can bypass a $mime_filename extension-blocking protection mechanism, and potentially deliver executable attachments to the mailboxes of end users.

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CVSS v3.1 Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Weakness Type (CWE)

CWE-116 CWE-116

Affected Products

Vendor	Product	Versions
exim	exim	< 4.97.1

References

Advisories & Patches

https://bugs.exim.org/show_bug.cgi?id=3099#c4 https://git.exim.org/exim.git/commit/1b3209b0577a9327ebb076f3b32b8a159c253f7b https://git.exim.org/exim.git/commit/6ce5c70cff8989418e05d01fd2a57703007a6357 https://bugs.exim.org/show_bug.cgi?id=3099#c4 https://git.exim.org/exim.git/commit/1b3209b0577a9327ebb076f3b32b8a159c253f7b https://git.exim.org/exim.git/commit/6ce5c70cff8989418e05d01fd2a57703007a6357

Exploits

https://bugs.exim.org/show_bug.cgi?id=3099#c4 https://bugs.exim.org/show_bug.cgi?id=3099#c4

Other References

https://github.com/Exim/exim/compare/exim-4.98-RC2...exim-4.98-RC3 https://www.rfc-editor.org/rfc/rfc2231.txt https://github.com/Exim/exim/compare/exim-4.98-RC2...exim-4.98-RC3 https://www.rfc-editor.org/rfc/rfc2231.txt

Frequently Asked Questions

What is CVE-2024-39929? +

Exim through 4.97.1 misparses a multiline RFC 2231 header filename, and thus remote attackers can bypass a $mime_filename extension-blocking protection mechanism, and potentially deliver executable attachments to the mailboxes of end users. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2024-39929? +

CVE-2024-39929 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-39929? +

CVE-2024-39929 affects products from exim, specifically: exim. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-39929? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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