CVE Vulnerabilities

CVE-2023-50781

Covert Timing Channel

Published: Feb 05, 2024 | Modified: Feb 25, 2026
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
7.5 MODERATE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Ubuntu
MEDIUM
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A flaw was found in m2crypto. This issue may allow a remote attacker to decrypt captured messages in TLS servers that use RSA key exchanges, which may lead to exposure of confidential or sensitive data.

Weakness

Covert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information.

Affected Software

NameVendorStart VersionEnd Version
Enterprise_linuxRedhat8.0 (including)8.0 (including)
Enterprise_linuxRedhat9.0 (including)9.0 (including)
M2cryptoUbuntubionic*
M2cryptoUbuntudevel*
M2cryptoUbuntuesm-apps/bionic*
M2cryptoUbuntuesm-apps/focal*
M2cryptoUbuntuesm-apps/jammy*
M2cryptoUbuntuesm-apps/noble*
M2cryptoUbuntufocal*
M2cryptoUbuntujammy*
M2cryptoUbuntulunar*
M2cryptoUbuntumantic*
M2cryptoUbuntunoble*
M2cryptoUbuntuoracular*
M2cryptoUbuntuplucky*
M2cryptoUbuntuquesting*
M2cryptoUbuntutrusty*
M2cryptoUbuntutrusty/esm*
M2cryptoUbuntuupstream*
M2cryptoUbuntuxenial*

Extended Description

In some instances, knowing when data is transmitted between parties can provide a malicious user with privileged information. Also, externally monitoring the timing of operations can potentially reveal sensitive data. For example, a cryptographic operation can expose its internal state if the time it takes to perform the operation varies, based on the state. Covert channels are frequently classified as either storage or timing channels. Some examples of covert timing channels are the system’s paging rate, the time a certain transaction requires to execute, and the time it takes to gain access to a shared bus.

Potential Mitigations

References