CVE-2023-50781 | M2crypto: bleichenbacher timing attacks in the rsa decryption api - incomplete fix for cve-2020-25657

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.

Published: 2024-02-05 Last update: 2026-05-12 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-50781 is rated Moderate Risk (52.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.44%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-50781

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-02 0.46% 0.44% -0.01%
2 2026-05-22 0.40% 0.46% +0.06%
3 2026-03-24 — 0.40% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-50781

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-50781

GitHub Security Advisory for CVE-2023-50781

GHSA-944j-8ch6-rf6x · Severity: medium · Ecosystem: pip — m2crypto Bleichenbacher timing attack - incomplete fix for CVE-2020-25657

OS Trackers for CVE-2023-50781

vendor priority summary link
debian not yet assigned CVE-2023-50781 not yet assigned priority: Debian including 1 source packages (m2crypto), 3 status rows across 3 suites (bookworm, bullseye, trixie): open 2, resolved 1. https://security-tracker.debian.org/tracker/CVE-2023-50781
redhat medium — https://access.redhat.com/security/cve/CVE-2023-50781
suse medium CVE-2023-50781 severity moderate: SUSE including 5 source package names (m2crypto, python-M2Crypto, python-m2crypto, python2-M2Crypto, python3-M2Crypto), 77 product×package rows across 42 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 7.1, … (42 product lines)): Will Not Fix 77. https://www.suse.com/security/cve/CVE-2023-50781/
ubuntu medium CVE-2023-50781 medium priority: Ubuntu including 1 source packages (m2crypto), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 10, needs-triage 2. https://ubuntu.com/security/CVE-2023-50781

Affected software / configurations for CVE-2023-50781

Vendor Product Version Raw CPE
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
redhat update_infrastructure 4 cpe:2.3:a:redhat:update_infrastructure:4:*:*:*:*:*:*:*
m2crypto_project m2crypto — cpe:2.3:a:m2crypto_project:m2crypto:-:*:*:*:*:*:*:*

References for CVE-2023-50781

cvelogic Threat Intelligence