Timing attack in m2crypto

1) Information Exposure Through Timing Discrepancy

EUVDB-ID: #VU104032

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 - Information Exposure Through Timing Discrepancy

Exploit availability: No

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

CPE2.3

• cpe:2.3:a:Ng Pheng Siong:m2crypto:0.11:*:*:*:*:*:*:*
• cpe:2.3:a:Ng Pheng Siong:m2crypto:0.13:*:*:*:*:*:*:*
• cpe:2.3:a:Ng Pheng Siong:m2crypto:0.15:*:*:*:*:*:*:*

External links

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

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.