CVE-2016-1494

Severity: medium (CVSS 5.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 7.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2016-01-13 · updated 2026-06-17
Weakness: CWE-20

Description

The verify function in the RSA package for Python (Python-RSA) before 3.3 allows attackers to spoof signatures with a small public exponent via crafted signature padding, aka a BERserk attack.

Affected products

Fedoraproject Fedora: 22, 23
openSUSE Leap: 42.1
Opensuse: 13.1, 13.2
Python Rsa: before 3.3 — fixed in 3.3

How to fix

Upgrade to a fixed version: Python Rsa 3.3. Check the vendor advisory for mitigations.

References

http://lists.fedoraproject.org/pipermail/package-announce/2016-January/175897.html
http://lists.fedoraproject.org/pipermail/package-announce/2016-January/175942.html
http://lists.opensuse.org/opensuse-updates/2016-01/msg00032.html
http://www.openwall.com/lists/oss-security/2016/01/05/1
http://www.openwall.com/lists/oss-security/2016/01/05/3
http://www.securityfocus.com/bid/79829
https://bitbucket.org/sybren/python-rsa/pull-requests/14/security-fix-bb06-attack-in-verify-by/diff
https://blog.filippo.io/bleichenbacher-06-signature-forgery-in-python-rsa/
http://lists.fedoraproject.org/pipermail/package-announce/2016-January/175897.html
http://lists.fedoraproject.org/pipermail/package-announce/2016-January/175942.html
http://lists.opensuse.org/opensuse-updates/2016-01/msg00032.html
http://www.openwall.com/lists/oss-security/2016/01/05/1

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