#VU57554 Integer overflow in strongSwan - CVE-2021-41990

Vulnerability identifier: #VU57554

Vulnerability risk: High

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:Amber]

CVE-ID: CVE-2021-41990

CWE-ID: CWE-190

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
strongSwan
Server applications / Encryption software

Vendor: strongswan.org

Description

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

The vulnerability exists due to integer overflow when processing a crafted certificate with an RSASSA-PSS signature. A remote attacker can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

strongSwan: 5.0.0 - 5.9.3

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External links
https://github.com/strongswan/strongswan/releases/tag/5.9.4
https://www.strongswan.org/blog/2021/10/18/strongswan-vulnerability-(cve-2021-41990).html
https://www.debian.org/security/2021/dsa-4989

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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.