Remote Code Execution in Apache Shiro (CVE‑2016‑4437) Bypasses “Remember Me” Feature
What It Is – Apache Shiro’s “remember‑me” functionality can be left without a cipher key. An attacker can supply a crafted request parameter that triggers remote code execution or bypasses intended access controls.
Exploitability – The flaw is remotely exploitable without authentication. Public proof‑of‑concept code exists; NVD rates the CVSS v3 base score at 7.5 (High).
Affected Products – Apache Shiro (any version prior to the vendor‑released fix; see Apache security advisory).
Why It Matters for Trust & Control Assurance
- Access‑control integrity – Un‑keyed “remember‑me” tokens allow attackers to assume any user identity, undermining authentication assurance.
- Configuration hygiene – The issue surfaces when critical security settings are left at defaults, highlighting the need for continuous configuration monitoring.
- Supply‑chain visibility – Many SaaS and enterprise applications embed Shiro; without an up‑to‑date component inventory, organizations cannot prove they have mitigated this risk to auditors.
Recommended Actions
- Inventory all applications that embed Apache Shiro; add the library to your SBOM.
- Upgrade to the patched version or apply the vendor’s configuration guidance to enforce a strong cipher key for “remember‑me”.
- Implement continuous monitoring of third‑party component versions and configuration drift.
- Capture remediation evidence (patch logs, configuration snapshots) for audit trails.
Source: CISA KEV – CVE‑2016‑4437