#VU31347 Improper Verification of Cryptographic Signature in SimpleSAMLphp - CVE-2018-7644

Vulnerability identifier: #VU31347

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2018-7644

CWE-ID: CWE-347

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
SimpleSAMLphp
Web applications / Other software

Vendor: SimpleSAMLphp

Description

The vulnerability allows a remote non-authenticated attacker to manipulate data.

The XmlSecLibs library as used in the saml2 library in SimpleSAMLphp before 1.15.3 incorrectly verifies signatures on SAML assertions, allowing a remote attacker to construct a crafted SAML assertion on behalf of an Identity Provider that would pass as cryptographically valid, thereby allowing them to impersonate a user from that Identity Provider, aka a key confusion issue.

Mitigation
Install update from vendor's website.

Vulnerable software versions

SimpleSAMLphp: 1.15.0 - 1.15.2

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External links
https://simplesamlphp.org/security/201802-01

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.