#VU85623 Information Exposure Through Timing Discrepancy in GnuTLS - CVE-2024-0553

Vulnerability identifier: #VU85623

Vulnerability risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2024-0553

CWE-ID: CWE-208

Exploitation vector: Network

Exploit availability: No

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

Vendor: GnuTLS

Description

The vulnerability allows a remote attacker to perform timing attack.

The vulnerability exists due to the response times to malformed ciphertexts in RSA-PSK ClientKeyExchange differ from response times of ciphertexts with correct PKCS#1 v1.5 padding. A remote attacker can perform timing sidechannel attack in RSA-PSK key exchange.

Note, the vulnerability exists due to incomplete fox for #VU83316 (CVE-2023-5981).

Mitigation
Install updates from vendor's website.

Vulnerable software versions

GnuTLS: 3.8.0 - 3.8.2

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External links
https://access.redhat.com/security/cve/CVE-2024-0553
https://bugzilla.redhat.com/show_bug.cgi?id=2258412
https://gitlab.com/gnutls/gnutls/-/issues/1522
https://lists.gnupg.org/pipermail/gnutls-help/2024-January/004841.html
https://www.openwall.com/lists/oss-security/2024/01/19/3

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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.