#VU104032 Information Exposure Through Timing Discrepancy in M2Crypto - CVE-2023-50781

Vulnerability identifier: #VU104032

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-50781

CWE-ID: CWE-208

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
M2Crypto
Other software / Other software solutions

Vendor: Ng Pheng Siong

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to possibility of the Bleichenbacher timing attack in the RSA decryption API via the timed processing of valid PKCS#1 v1.5 Ciphertext. A remote attacker can gain access to sensitive information.

Note, the vulnerability exists due ti incomplete fix for #VU65771 (CVE-2020-25657).

Mitigation

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

The vulnerability is partially solved with OpenSSL update if the default provider is in use (e.g. won't help with pkcs11 provider).

Vulnerable software versions

M2Crypto: 0.11 - 0.44.0

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External links
https://access.redhat.com/security/cve/CVE-2023-50781
https://bugzilla.redhat.com/show_bug.cgi?id=2254426

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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.