CVE-2017-12868 SimpleSAMLphp Session fixation issue and authentication bypass in the authcrypt module

What is CVE-2017-12868?

CVE-2017-12868 is a critical authentication bypass vulnerability in n/a, published on 1 Sep 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The secureCompare method in lib/SimpleSAML/Utils/Crypto.php in SimpleSAMLphp 1.14.13 and earlier, when used with PHP before 5.6, allows attackers to conduct session fixation attacks or possibly bypass authentication by leveraging missing character conversions before an XOR operation.

Weakness: CWE-384

Which versions are affected by CVE-2017-12868?

2 open source packages ship an affected version, including simplesamlphp/simplesamlphp. It affects 1 product.

Products include Simplesamlphp Simplesamlphp.

How do I fix CVE-2017-12868?

Upgrade simplesamlphp/simplesamlphp to 1.14.14 or later.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2017-12868 being exploited?

There is no known exploitation of CVE-2017-12868 in the wild and no public exploit code.

Other vulnerabilities in n/a

• CVE-2018-7644 SimpleSAMLphp Improper Verification of Cryptographic Signature High 7.5
• CVE-2026-49284 SimpleSAMLphp SP accepts a response from an unexpected IdP when unsigned `Response/InResponseTo` is combined with a signed assertion lacking `SubjectConfirmationData/InResponseTo` High 7.1
• CVE-2018-6520 SimpleSAMLphp Open redirection protection bypass Medium 6.1
• CVE-2017-12870 SimpleSAMLphp Unauthenticated encryption in CBC mode Medium 5.9
• CVE-2017-12871 SimpleSAMLphp Incorrect IV generation for encryption Medium 5.9

Sources

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

Also known as DEBIAN-CVE-2017-12868, GHSA-j96g-47x2-46hv, UBUNTU-CVE-2017-12868.