CVE-2023-50782
python-cryptography: Bleichenbacher timing oracle attack against RSA decryption - incomplete fix for CVE-2020-25659
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · December 13, 2023
Updated · March 24, 2026
Description
A flaw was found in the python-cryptography package. 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.
Statement
This vulnerability exists due to an incomplete fix for CVE-2020-25659.
The CVE-2020-25659 vulnerability presents a moderate severity concern due to its specific impact on applications utilizing RSA decryption with PKCS#1 v1.5 padding. While the vulnerability could potentially lead to leakage in RSA decryption operations, its severity is downgraded to moderate by several factors. Firstly, the exploitability of the vulnerability is limited to scenarios where RSA decryption with PKCS#1 v1.5 padding is employed, narrowing the scope of affected systems. Additionally, the implementation of implicit rejection, such as the Marvin workaround, provides a viable mitigation strategy.
https://people.redhat.com/~hkario/marvin/
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE-203 · Observable Discrepancy