# CVE-2016-4312: XML external entity in n/a

> Authenticated attackers can exploit an XXE vulnerability in WSO2 Identity Server to read arbitrary files or cause denial of service via crafted XACML requests.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Feb 2017
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-rx7g-4gvj-h8m6

## What is CVE-2016-4312?

CVE-2016-4312 is a high-severity vulnerability in Wso2 Identity Server, published on 16 Feb 2017. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

XML external entity (XXE) vulnerability in the XACML flow feature in WSO2 Identity Server 5.1.0 before WSO2-CARBON-PATCH-4.4.0-0231 allows remote authenticated users with access to XACML features to read arbitrary files, cause a denial of service, conduct server-side request forgery (SSRF) attacks, or have unspecified other impact via a crafted XACML request to entitlement/eval-policy-submit.jsp.  NOTE: this issue can be combined with CVE-2016-4311 to exploit the vulnerability without credentials.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2016-4312?

It affects 1 product.


Products: Wso2 Identity Server.

## How do I fix CVE-2016-4312?

No fix has been published for CVE-2016-4312 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-4312 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-4312 exists.

Public exploit code:

- WSO2 Identity Server 5.1.0 - Multiple Vulnerabilities (exploitdb)

## Other vulnerabilities in Wso2 Identity Server

- [CVE-2016-4311](https://insights.sbomify.com/CVE-2016-4311/): Cross-site request forgery in n/a (high 8.8)
- [CVE-2025-10470](https://insights.sbomify.com/CVE-2025-10470/): Denial-of-Service via Magic Link Authentication in WSO2 Identity Server Allows Service Unavailability (high 8.6)
- [CVE-2025-12107](https://insights.sbomify.com/CVE-2025-12107/): Server-Side Template Injection via Velocity Template Engine in Multiple WSO2 Products Allows Remote Code Execution (high 8.4)
- [CVE-2025-10908](https://insights.sbomify.com/CVE-2025-10908/): Account Lock Bypass via Magic Link or Pass Key Authentication in WSO2 Identity Server Allows Unauthorized Access (high 7.3)
- [CVE-2025-0663](https://insights.sbomify.com/CVE-2025-0663/): Auth bypass in WSO2 Identity Server (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-4312 and fix it if it is affected.

What it is: CVE-2016-4312 is a high-severity vulnerability in Wso2 Identity Server, published on 16 Feb 2017. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-4312 exists.

Affected product: Wso2 Identity Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2016-4312/ (Markdown: https://insights.sbomify.com/CVE-2016-4312/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-4312
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-4312
- OSV: https://osv.dev/vulnerability/CVE-2016-4312

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-4312/
Summaries are generated and may contain mistakes; the official description above is the record.