Threats / Apache / CVE-2016-4437
CVE-2016-4437
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Apache Shiro vulnerability
Apache Shiro contains an access control vulnerability in the remember-me feature that allows remote attackers to execute code or bypass authentication when a cipher key is not configured.
Verdict
Today item — known-exploited.
An unauthenticated remote attacker can exploit improper access controls in Shiro's remember-me mechanism to bypass authentication or achieve code execution by crafting malicious request parameters when cryptographic key configuration is absent.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
1 independent public report of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
Probability (EPSS)
EPSS 0.93143 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Apache, Shiro. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-284 Improper Access Control — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a request with a malicious remember-me parameter to a Shiro-protected application lacking cipher key configuration.
Business
Unauthorized access to user accounts and application resources is gained without valid credentials.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I exploit the unencrypted or improperly validated remember-me token to inject code or escalate privileges within the application.
Business
Attackers achieve remote code execution, enabling full system compromise and data exfiltration.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05