high
7.5
CWE
20
Advisory Published
CVE Published
Advisory Published
Updated

CVE-2018-10903: Input Validation

First published: Wed Jul 18 2018(Updated: )

A flaw was found in python-cryptography versions between &gt;=1.9.0 and &lt;2.3. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage. Upstream patch: <a href="https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef">https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef</a> References: <a class="bz_bug_link bz_status_CLOSED bz_closed bz_public " title="CLOSED ERRATA - Possible tag truncation security bug in AEAD API" href="show_bug.cgi?id=1602752">https://bugzilla.redhat.com/show_bug.cgi?id=1602752</a>

Credit: secalert@redhat.com secalert@redhat.com

Affected SoftwareAffected VersionHow to fix
redhat/python-cryptography<2.3
2.3
pip/cryptography>=1.9.0<2.3
2.3
debian/python-cryptography
3.3.2-1
38.0.4-3
38.0.4-3~deb12u1
42.0.5-2
43.0.0-1
Python-cryptography>=1.9.0<2.3
Red Hat OpenStack for IBM Power=13
Ubuntu=18.04

Remedy

https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10903

Remedy

https://github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f00ab19ef

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2018-10903?

    CVE-2018-10903 has a severity rating of medium due to the potential for attackers to exploit the inadequate tag length enforcement.

  • How do I fix CVE-2018-10903?

    To fix CVE-2018-10903, update python-cryptography to version 2.3 or later.

  • Which versions of python-cryptography are affected by CVE-2018-10903?

    Versions of python-cryptography between 1.9.0 and 2.2 are affected by CVE-2018-10903.

  • What could an attacker achieve by exploiting CVE-2018-10903?

    An attacker could potentially craft an invalid payload leading to security vulnerabilities due to improper input validation in the finalize_with_tag API.

  • Is CVE-2018-10903 related to specific operating systems?

    Yes, CVE-2018-10903 affects installations of python-cryptography on various operating systems including Red Hat and Ubuntu.

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