CVE-2016-5388 is a high-severity (CVSS 8.1) CWE-284 vulnerability in org.apache.tomcat:tomcat-catalina. EPSS puts its 30-day exploitation probability at 50.9% (99th percentile). A fix is available for org.apache.tomcat:tomcat-catalina — see the affected versions and patch details below.
Improper Access Control in Apache Tomcat
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2016-5388.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.apache.tomcat:tomcat-catalina☕org.apache.tomcat:tomcat-catalinaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Apache Tomcat 7.x through 7.0.70 and 8.x through 8.5.4, when the CGI Servlet is enabled, follows RFC 3875 section 4.1.18 and therefore does not protect applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect an application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue. NOTE: the vendor states "A mitigation is planned for future releases of Tomcat, tracked as CVE-2016-5388"; in other words, this is not a CVE ID for a vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat-catalina | ≥ 7.0.0&&< 7.0.72 | 7.0.72org.apache.tomcat:tomcat-catalina:7.0.72 |
| ☕Maven | org.apache.tomcat:tomcat-catalina | ≥ 8.0.0&&< 8.5.5 | 8.5.5org.apache.tomcat:tomcat-catalina:8.5.5 |
Affected Products
tomcatapachesystem management homepagehplinuxoracleenterprise linux desktopredhatenterprise linux hpc noderedhatenterprise linux hpc node eusredhatDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat-catalina, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat-catalina to 7.0.72 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-5388 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 6 | tomcat6-0:6.0.24-98.el6_8 | RHSA-2016:2045 |
| Red Hat Enterprise Linux 7 | tomcat-0:7.0.54-8.el7_2 | RHSA-2016:2046 |
| Red Hat JBoss Web Server 3.0 | see advisory | RHSA-2016:1624 |
| Red Hat JBoss Web Server 3 for RHEL 6 | httpd24-0:2.4.6-62.ep7.el6 | RHSA-2016:1636 |
| Red Hat JBoss Web Server 3 for RHEL 7 | httpd24-0:2.4.6-62.ep7.el7 | RHSA-2016:1635 |
Frequently Asked Questions
Is CVE-2016-5388 in your dependencies?
Find it across Maven, including transitive dependencies.