GHSA-fvcv-3m26-pcqx
MEDIUMGHSA-fvcv-3m26-pcqx is a medium-severity (CVSS 4.8) vulnerability in axios. O3 Security confirms whether GHSA-fvcv-3m26-pcqx is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Axios has Unrestricted Cloud Metadata Exfiltration via Header Injection Chain
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
axiosnpmDescription
Vulnerability Disclosure: Unrestricted Cloud Metadata Exfiltration via Header Injection Chain
Summary
The Axios library is vulnerable to a specific gadget-style attack chain in which prototype pollution in a third-party dependency may be leveraged to inject unsanitized header values into outbound requests.
Axios can be used as a gadget after pollution occurs elsewhere because header values merged from attacker-controlled prototype properties are not sanitized for CRLF (\r\n) characters before being written to the request. In affected deployments, this may enable limited request manipulation or metadata access as part of a higher-complexity exploit chain.
Severity: Moderate (CVSS 3.1 Base Score: 4.8)
Affected Versions: All versions (v0.x - v1.x)
Vulnerable Component: lib/adapters/http.js (Header Processing)
Usage of "Helper" Vulnerabilities
This issue requires a separate prototype pollution vulnerability in another library in the application stack (for example, qs, minimist, ini, or body-parser). If an attacker can pollute Object.prototype, Axios may pick up the polluted properties during config merge.
Because Axios does not sanitise these merged header values for CRLF (\r\n) characters, the polluted property can alter the structure of an outbound HTTP request.
Proof of Concept
1. The Setup (Simulated Pollution)
Imagine a scenario where a known vulnerability exists in a query parser. The attacker sends a payload that sets:
Object.prototype['x-amz-target'] = \"dummy\r\n\r\nPUT /latest/api/token HTTP/1.1\r\nHost: 169.254.169.254\r\nX-aws-ec2-metadata-token-ttl-seconds: 21600\r\n\r\nGET /ignore\";
2. The Gadget Trigger (Safe Code)
The application makes a completely safe, hardcoded request:
// This looks safe to the developer
await axios.get('https://analytics.internal/pings');
3. The Execution
Axios merges the prototype property x-amz-target into the request headers. It then writes the header value directly to the socket without validation.
Resulting HTTP traffic:
GET /pings HTTP/1.1
Host: analytics.internal
x-amz-target: dummy
PUT /latest/api/token HTTP/1.1
Host: 169.254.169.254
X-aws-ec2-metadata-token-ttl-seconds: 21600
GET /ignore HTTP/1.1
...
4. The Impact
In environments where requests can reach cloud metadata endpoints or sensitive internal services, the injected header content may help bypass expected request constraints and expose limited credentials or modify request semantics. This impact depends on application context and a separate prototype-pollution primitive.
Impact Analysis
- Confidentiality: May expose limited sensitive information in affected network environments.
- Integrity: May allow modification of outbound request structure or injected headers.
- Attack Complexity: Exploitation requires a separate prototype-pollution vulnerability and a reachable target service.
Recommended Fix
Validate all header values in lib/adapters/http.js and xhr.js before passing them to the underlying request function.
Patch Suggestion:
// In lib/adapters/http.js
utils.forEach(requestHeaders, function setRequestHeader(val, key) {
if (/[\r\n]/.test(val)) {
throw new Error('Security: Header value contains invalid characters');
}
// ... proceed to set header
});
References
- OWASP: CRLF Injection (CWE-113)
This report was generated as part of a security audit of the Axios library.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | axios | ≥ 1.0.0&&< 1.15.0 | 1.15.0 |
| 📦npm | axios | all versions | 0.31.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for axios. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update axios to 1.15.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fvcv-3m26-pcqx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-fvcv-3m26-pcqx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-fvcv-3m26-pcqx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-fvcv-3m26-pcqx in your dependencies?
O3 detects GHSA-fvcv-3m26-pcqx across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.