#VU65771 Information Exposure Through Timing Discrepancy in M2Crypto - CVE-2020-25657

Vulnerability identifier: #VU65771

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-25657

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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

M2Crypto: 0.11 - 0.38.0

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External links
http://bugzilla.redhat.com/show_bug.cgi?id=1889823
http://gitlab.com/m2crypto/m2crypto/-/issues/282

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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.