CVE-2020-5390 Improper Verification of Cryptographic Signature in PySAML2

What is CVE-2020-5390?

CVE-2020-5390 is a high-severity vulnerability in Canonical Ubuntu Linux, published on 13 Jan 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

PySAML2 before 5.0.0 does not check that the signature in a SAML document is enveloped and thus signature wrapping is effective, i.e., it is affected by XML Signature Wrapping (XSW). The signature information and the node/object that is signed can be in different places and thus the signature verification will succeed, but the wrong data will be used. This specifically affects the verification of assertion that have been signed.

Weakness: CWE-347

Which versions are affected by CVE-2020-5390?

3 open source packages ship an affected version, including pysaml2. It affects 3 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Pysaml2 Project Pysaml2.

How do I fix CVE-2020-5390?

Upgrade pysaml2 to 5.0.0 or later.

Is CVE-2020-5390 being exploited?

There is no known exploitation of CVE-2020-5390 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-5390, DLA-2119-1, DSA-4630-1, GHSA-qf7v-8hj3-4xw7, PYSEC-2020-94, UBUNTU-CVE-2020-5390 and 1 more.