Apache Shiro Code Execution
CVE-2016-4437 is a critical-severity use of hard-coded cryptographic key vulnerability in Aurora from Apache, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 0.18.1 as the first without the flaw, so updating Aurora to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on November 3, 2021, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Aurora to 0.18.1 or a later version.
- Update Shiro to 1.2.5 or a later version.
- CISA's required action: Apply updates per vendor instructions.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Aurora | 0.10.0 up to, but not including, 0.18.1 | 0.18.1 |
| Apache | Shiro | before 1.2.5 | 1.2.5 |
| Red Hat | Fuse | 1.0 | Not stated |
| Red Hat | Jboss Middleware Text-only Advisories | 1.0 | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 3.1 | 9.8 | Critical | CISA (ADP) |
| CVSS 2.0 | 6.8 | Medium | NVD |
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Hard-coded Cryptographic Key
The product uses a hard-coded, unchangeable cryptographic key.
How developers prevent this class of flaw
- Prevention schemes mirror that of hard-coded password storage.
More Use of Hard-coded Cryptographic Key vulnerabilities (CWE-321)
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- packetstormsecurity.com/files/137310/Apache-Shiro-1.2.4-Information-Disclosure.htmlThird Party Advisory, VDB Entry
- rhn.redhat.com/errata/RHSA-2016-2035.htmlThird Party Advisory
- rhn.redhat.com/errata/RHSA-2016-2036.htmlThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2016-4437US Government Resource
Technical write-ups (may include proof of concept)
- packetstormsecurity.com/files/157497/Apache-Shiro-1.2.4-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
Other references
Other vulnerabilities in Aurora
- 9.1 Critical severity
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