#VU81254 Buffer overflow in Exim - CVE-2023-42117

Vulnerability identifier: #VU81254

Vulnerability risk: Critical

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Red]

CVE-ID: CVE-2023-42117

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Exim
Server applications / Mail servers

Vendor: Exim

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error within the smtp service. A remote attacker can send specially crafted data to the server, trigger memory corruption and execute arbitrary code on the target system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Exim: 4.00 - 4.96

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External links
https://www.zerodayinitiative.com/advisories/ZDI-23-1471/
https://www.exim.org/static/doc/security/CVE-2023-zdi.txt

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.