Description
ILIAS deserialises stored session data for an unauthenticated caller. The Shibboleth back-channel endpoint at components/ILIAS/AuthShibboleth/resources/shib_logout.php runs in a context that ilInitialisation exempts from authentication, and its logout-notification handler locates the session to terminate by reading every live row of the session table and passing each row's stored data to a hand-written parser that calls unserialize without restricting which classes may be constructed. Any serialised object present in any session row is therefore instantiated on behalf of an anonymous request, and object destructors run when those objects are discarded. A serialised object can be placed into a session row without logging in, because the LTI authentication entry point stores request parameters into the session and is reachable on a path the same initialisation code exempts from authentication. A class bundled with the application writes a JSON-encoded structure to a file named by one of its own properties when it is destroyed, which places attacker-controlled content at an attacker-chosen path below the web root and results in code execution as the web server user. Versions 9.22, 10.10 and 11.3 remove the endpoint's logout-notification implementation.
Published: 2026-08-26
Score: 9.3 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Wed, 26 Aug 2026 16:00:00 +0000

Type Values Removed Values Added
Description ILIAS deserialises stored session data for an unauthenticated caller. The Shibboleth back-channel endpoint at components/ILIAS/AuthShibboleth/resources/shib_logout.php runs in a context that ilInitialisation exempts from authentication, and its logout-notification handler locates the session to terminate by reading every live row of the session table and passing each row's stored data to a hand-written parser that calls unserialize without restricting which classes may be constructed. Any serialised object present in any session row is therefore instantiated on behalf of an anonymous request, and object destructors run when those objects are discarded. A serialised object can be placed into a session row without logging in, because the LTI authentication entry point stores request parameters into the session and is reachable on a path the same initialisation code exempts from authentication. A class bundled with the application writes a JSON-encoded structure to a file named by one of its own properties when it is destroyed, which places attacker-controlled content at an attacker-chosen path below the web root and results in code execution as the web server user. Versions 9.22, 10.10 and 11.3 remove the endpoint's logout-notification implementation.
Title ILIAS before 9.22, 10.10 and 11.3 Unauthenticated PHP Object Injection via Shibboleth Logout Endpoint
First Time appeared Ilias
Ilias ilias
Weaknesses CWE-502
CPEs cpe:2.3:a:ilias:ilias:*:*:*:*:*:*:*:*
Vendors & Products Ilias
Ilias ilias
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

Ilias Ilias
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-26T15:44:55.917Z

Reserved: 2026-08-26T10:43:44.175Z

Link: CVE-2026-80428

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-26T16:16:45.100

Modified: 2026-08-26T16:16:45.100

Link: CVE-2026-80428

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-502

    Deserialization of Untrusted Data