CVE-2016-4437
CriticalExploitedPublic exploitImproper Access Control in Apache Shiro
Published May 14, 2022 · Updated Sep 30, 2026 · Also known as DEBIAN-CVE-2016-4437, GHSA-p836-389h-j692, UBUNTU-CVE-2016-4437
Key Facts
Patch immediately- CVE-2016-4437 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Aurora (Apache), Shiro (Apache), Fuse (Redhat) and 2 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Nov 3, 2021. Public exploit code is available.
- EPSS estimates a 93% probability of exploitation in the next 30 days.
- Fixed versions are available, including Aurora 0.18.1, Shiro 1.2.5, Shiro 1.2.4-1ubuntu0.1~esm1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
93%
Higher than 99.8% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2016-4437 brief as a PDF
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Nov 3, 2021 | May 3, 2022 | Not reported |
| Industry KEV feed | Nov 3, 2021 | May 3, 2022 | Not reported |
| CIRCL KEV | Nov 3, 2021 | May 3, 2022 | Not reported |
| ENISA EUVD | Nov 3, 2021 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
16 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| AuroraApache | See advisory | 0.18.1 |
| ShiroApache | See advisory | 1.2.5 |
| FuseRedhat | 1.0 | n/a |
| Jboss Middleware Text-Only AdvisoriesRedhat | 1.0 | n/a |
| org.apache.shiro:shiro-coremaven | See advisory | 1.2.5 |
Patched Releases
Aurora
0.18.1
Shiro
1.2.5, 1.2.4-1ubuntu0.1~esm1, 1.2.5-1
org.apache.shiro:shiro-core
1.2.5
Timeline
Added to CISA KEV
Nov 3, 2021
Added to Industry KEV feed
Nov 3, 2021
Added to CIRCL KEV
Nov 3, 2021
Added to ENISA EUVD
Nov 3, 2021
Publicly disclosed
May 14, 2022
Last updated
Sep 30, 2026
Weakness Type
- CWE-284 Improper Access Control
- CWE-287 Improper Authentication
- CWE-321 Use of Hard-coded Cryptographic Key
References
- advisoryRHSA-2016:2035
- advisoryRHSA-2016:2036
- advisoryGHSA advisory
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2016-4437
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2016-4437
FAQ
Common Questions.
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.
Affected: Aurora (Apache); Shiro (Apache); Fuse (Redhat) versions 1.0, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Nov 3, 2021.
Yes. It was added on Nov 3, 2021 with a federal remediation due date of May 3, 2022.
Public exploit code is available.
Fixed versions are available, including Aurora 0.18.1, Shiro 1.2.5, Shiro 1.2.4-1ubuntu0.1~esm1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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