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Fencer Intel
medium 5.9

CVE-2020-25657 json

A flaw was found in all released versions of m2crypto, where they are vulnerable to Bleichenbacher timing attacks in the RSA decryption API…

published 5y ago modified 4mo ago also EUVD-2020-18321

cvss
5.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

Summary

A flaw was found in all released versions of m2crypto, where they are vulnerable to Bleichenbacher timing attacks in the RSA decryption API via the timed processing of valid PKCS#1 v1.5 Ciphertext. The highest threat from this vulnerability is to confidentiality.

Patch / fix

  • m2crypto Debian 13, Debian 12 0.38.0-4

debian advisories DEBIAN-CVE-2020-25657

  • rhvm rhev manager 4.4 4.4.5.9-0.1.el8ev
  • ovirt-engine rhev manager 4.4 4.4.5.9-0.1.el8ev
  • ovirt-web-ui rhev manager 4.4 1.6.7-1.el8ev
  • ovirt-engine-setup rhev manager 4.4 4.4.5.9-0.1.el8ev
  • ovirt-engine-tools rhev manager 4.4 4.4.5.9-0.1.el8ev
  • ovirt-engine-backend rhev manager 4.4 4.4.5.9-0.1.el8ev
  • ovirt-engine-restapi rhev manager 4.4 4.4.5.9-0.1.el8ev
  • ovirt-engine-dbscripts rhev manager 4.4 4.4.5.9-0.1.el8ev

red hat advisories RHSA-2021:1169

  • python3-M2Crypto SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +10 more 0.44.0-150400.13.1
  • python3-M2Crypto SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 0.44.0-150600.19.3.1
  • python-M2Crypto SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Module for Python 3 15 SP5 +3 more 0.40.0-150400.3.9.1
  • python-M2Crypto SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 0.38.0-150400.3.6.1
  • python-M2Crypto SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES for SAP 15 +23 more 0.35.2-150000.3.14.1
  • python-M2Crypto SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 0.38.0-150400.3.3.1
  • python-M2Crypto SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +6 more 0.29.0-23.8.1

suse advisories SUSE-RU-2025:0800-1SUSE-RU-2025:0796-1SUSE-FU-2024:1448-1SUSE-SU-2022:2691-1SUSE-SU-2022:2562-1SUSE-SU-2022:2532-1

  • python-M2Crypto openSUSE Leap Micro 5.2 0.35.2-150000.3.14.1

opensuse advisories openSUSE-SU-2022:2562-1

  • m2crypto CBL-Mariner 2.0, Azure Linux 3.0 0.38.0-3

azure linux advisories AZL-10076AZL-34969

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-25657 updated cvss 7.5

m2crypto: bleichenbacher timing attacks in the RSA decryption API

  • Red Hat Enterprise Linux 6 m2crypto Red Hat Enterprise Linux 7 m2crypto
    affected: no fix planned “Out of support scope”
  • Red Hat RHEL-8-RHEV-S-4.4 - Red Hat Virtualization Engine 4.4 rhvm 4.4.5.9-0.1.el8ev, ovirt-engine 4.4.5.9-0.1.el8ev, ovirt-engine-setup 4.4.5.9-0.1.el8ev, ovirt-engine-tools 4.4.5.9-0.1.el8ev, ovirt-engine-backend 4.4.5.9-0.1.el8ev, ovirt-engine-restapi 4.4.5.9-0.1.el8ev, +14 more
    fixed: vendor fix RHSA-2021:1169
  • Red Hat RHEL-8-RHEV-S-4.4 - Red Hat Virtualization Engine 4.4 apache-sshd 2.6.0-1.el8ev, ovirt-web-ui 1.6.7-1.el8ev, ansible-runner 1.4.6-2.el8ar, ovirt-engine-dwh 4.4.5.5-1.el8ev, apache-sshd-javadoc 2.6.0-1.el8ev, ansible-runner-service 1.0.7-1.el8ev, +3 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.76% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

Affected products

  • n/a m2crypto

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.