Vulnerability identifier: #VU56063

Vulnerability risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3711

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenSSL
Server applications / Encryption software

Vendor: OpenSSL Software Foundation

Description

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

The vulnerability exists due to a boundary error in EVP_PKEY_decrypt() function within implementation of the SM2 decryption. A remote attacker can send specially crafted SM2 content for decryption to trigger a buffer overflow by 62 bytes 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

OpenSSL: 1.1.1 - 1.1.1k

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External links
http://www.openssl.org/news/secadv/20210824.txt
http://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=59f5e75f3bced8fc0e130d72a3f582cf7b480b46

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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.