#VU50252 Out-of-bounds write in wolfSSL - CVE-2020-36177

Vulnerability identifier: #VU50252

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-2020-36177

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
wolfSSL
Universal components / Libraries / Libraries used by multiple products

Vendor: wolfSSL

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input for certain relationships between key size and digest size within the RsaPad_PSS() function in wolfcrypt/src/rsa.c in wolfSSL. A remote attacker can send specially crafted data to the application, trigger out-of-bounds write and execute arbitrary code on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

wolfSSL: 2.0.3 - 4.5.0

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External links
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=26567
https://github.com/wolfSSL/wolfssl/commit/63bf5dc56ccbfc12a73b06327361687091a4c6f7
https://github.com/wolfSSL/wolfssl/commit/fb2288c46dd4c864b78f00a47a364b96a09a5c0f
https://github.com/wolfSSL/wolfssl/pull/3426
https://github.com/wolfSSL/wolfssl/releases/tag/v4.6.0-stable

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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.