Vulnerability identifier: #VU69579

Vulnerability risk: Medium

CVSSv3.1: 6.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:U/RC:C]

CVE-ID: CVE-2022-3559

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Exim
Server applications / Mail servers

Vendor: Exim

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error in the regex handler. A remote attacker can send specially crafted data to the mail server, trigger a use-after-free error and perform a denial of service (DoS) attack.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

Exim: 4.87 - 4.96

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External links
http://git.exim.org/exim.git/commit/4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2
http://bugs.exim.org/show_bug.cgi?id=2915
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WFHLZVHNNO2GWYP5EA4TZQZ5O4GVPARR/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TMQ6OCKPNPBPSD37YR4FOWV2R54M2UEP/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EIH4W5R7SHTUEQFWWKB4TUO5YFZX64KV/

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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.