CVE-2025-24813 is a path equivalence vulnerability in Apache Tomcat. CISA added it to the Known Exploited Vulnerabilities catalogue on 1 April 2025, which means attackers have used it in real attacks. Apache Tomcat contains a path equivalence vulnerability that allows a remote attacker to execute code, disclose information, or inject malicious content via a partial PUT request.
What Makes Path Equivalence Dangerous in Apache Tomcat
Path equivalence flaws let attackers describe the same resource in more than one way, then slip past security checks that rely on a single canonical path. In Apache Tomcat, that matters because an apparently ordinary request can be interpreted differently by routing, authorisation, upload, or file-handling logic.
The core danger is not just “bad input”, but inconsistent path normalisation. If one layer accepts a path as harmless while another resolves it to a sensitive location, an attacker can reach content or behaviour the application never meant to expose.
How the Vulnerability Becomes Remote Code Execution
For this CVE, the practical risk comes from a partial PUT request that can be used to execute code, disclose information, or inject malicious content. A request that looks like a file operation may instead become a vehicle for placing attacker-controlled content where Tomcat or the application will process it.
That is why path equivalence issues are especially severe in web servers and application containers: they can turn a file-path parsing mistake into a server-side execution problem. The underlying weakness is often a mismatch between path validation, request mapping, and the eventual file-system or application interpretation of the target path.
For vulnerability reference and canonical record details, consult the CVE Program and the NIST National Vulnerability Database.
How Organisations Check Exposure and Reduce Attack Surface
Exposure review starts with asset inventory, because you cannot judge risk if you do not know which Tomcat instances are reachable, which are internet-facing, and which applications rely on file upload or request-to-file workflows. Vendor advisories should be read alongside environment-specific configuration, since deployment pattern often matters as much as product version.
Path equivalence issues are rarely isolated to one endpoint. Teams should look for request paths that reach upload handlers, content repositories, admin functions, or anything that stores or executes files in a location Tomcat can later serve or interpret.
When a patch cannot be applied immediately, reduce exposure by narrowing who can reach the service, disabling unnecessary upload or PUT capability, and tightening any reverse-proxy or web-server normalisation rules that sit in front of Tomcat.
Detection, Recovery, and Post-Exploit Review
Detection should focus on unusual PUT activity, suspicious file writes, unexpected web content changes, and follow-on requests that suggest a planted artefact is being executed or fetched. Because the weakness can support both code execution and content injection, look for both server-side modification and outward signs of compromise.
After remediation, review for persistence. A successful attacker may leave behind a web shell, modified application content, altered configuration, or other artefacts that survive the initial exploit path. If compromise is suspected, treat credentials, session material, and any application secrets exposed by the affected service as potentially at risk and rotate them as needed.
Risk and Threat Considerations
Path equivalence flaws are dangerous because they can defeat defences that assume one path representation is always the same as another. In a web application container, that can let an attacker smuggle an operation through a request the front end, proxy, or filter chain did not intend to allow.
Failure mechanism: The attacker supplies an alternate path form that passes one layer of validation but resolves differently inside Tomcat, allowing a partial PUT request to reach code execution, information disclosure, or malicious content injection.
Impact: Successful exploitation can lead to full server compromise, tampered web content, exposed data, and post-exploit persistence that remains even after the vulnerable request path is no longer in use.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK addresses the attack and risk surface, while OWASP ASVS, NIST SP 800-53 Rev 5 and CIS Controls v8 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP ASVS | V4 — API and Web Service | Path handling and request processing failures directly affect web service security. |
| Recommendation — Verify request routing and file-handling controls to block alternate-path abuse. | ||
| NIST SP 800-53 Rev 5 | SI-10 — Information Input Validation | Path equivalence exploits inconsistent handling of attacker-controlled input. |
| SI-3 — Malicious Code Protection | RCE and malicious content injection are central consequences of exploitation. | |
| Recommendation — Validate and canonicalize request paths before any security decision or file operation. Scan and restrict executable content paths to prevent malicious payload placement. | ||
| CIS Controls v8 | CIS-16 — Application Software Security | Tomcat path handling is an application-layer security concern requiring secure configuration and testing. |
| Recommendation — Test application paths for alternate encodings and normalise them before release. | ||
| MITRE ATT&CK | T1190 — Exploit Public-Facing Application | The vulnerability is exploitable over the network against a public-facing service. |
| Recommendation — Map exposed Tomcat services to T1190 and hunt for suspicious PUT-driven exploitation. | ||
Practitioner Guidance
Why practitioners should care: This CVE is not just a Tomcat hygiene issue, it can be an access-to-execution issue if the application accepts file-like requests from untrusted users. Treat any environment that allows uploads, content publication, or PUT semantics as higher priority until exposure is verified.
What to watch for: Watch for inconsistent path handling between edge components and Tomcat itself, especially when a proxy, WAF, or application filter makes a different normalisation decision than the server. That mismatch is where path equivalence bugs usually become exploitable.
Practitioner takeaway: Validate the full request path from ingress to storage, not just the URL string seen by the application, because the exploit path depends on how each layer resolves the same path differently.
Related resources from NHI Mgmt Group
- How should security teams reduce exposure to CVE-2025-24813 in Apache Tomcat before patching is complete?
- Why does CVE-2025-24813 create a serious risk when Tomcat uses file based session storage?
- What should teams look for when validating whether a Tomcat deployment is exposed to CVE-2025-24813?
- What breaks when React and Next.js applications expose the server-side deserialization path used in CVE-2025-55182?