# CVE-2017-1000071: Auth bypass in n/a

> An authentication bypass in phpCAS allows attackers to bypass validation when configured against old CAS servers, requiring an upgrade to secure the application.

- **Severity:** High 8.1 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Jul 2017
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2017-1000071, GHSA-fwrj-8jg7-7jr6, UBUNTU-CVE-2017-1000071

## What is CVE-2017-1000071?

CVE-2017-1000071 is a high-severity authentication bypass vulnerability in n/a, published on 13 Jul 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Jasig phpCAS version 1.3.4 is vulnerable to an authentication bypass in the validateCAS20 function when configured to authenticate against an old CAS server.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2017-1000071?

It affects 1 product.


Products: Apereo Phpcas.

## How do I fix CVE-2017-1000071?

Upgrade to a fixed version.

## Is CVE-2017-1000071 being exploited?

There is no known exploitation of CVE-2017-1000071 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2022-39369](https://insights.sbomify.com/CVE-2022-39369/): Service Hostname Discovery Exploitation in phpCAS (high 8.0)
- [CVE-2010-3692](https://insights.sbomify.com/CVE-2010-3692/): Path traversal in n/a (medium 6.4)
- [CVE-2012-5583](https://insights.sbomify.com/CVE-2012-5583/): Weak cryptography in n/a (medium 5.8)
- [CVE-2012-1105](https://insights.sbomify.com/CVE-2012-1105/): Information disclosure in php-pear-CAS (medium 5.5)
- [CVE-2012-1104](https://insights.sbomify.com/CVE-2012-1104/): Security feature bypass in phpCAS (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-1000071 and fix it if it is affected.

What it is: CVE-2017-1000071 is a high-severity authentication bypass vulnerability in n/a, published on 13 Jul 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2017-1000071 in the wild and no public exploit code.

Affected product: n/a. 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-2017-1000071/ (Markdown: https://insights.sbomify.com/CVE-2017-1000071/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-1000071
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-1000071
- OSV: https://osv.dev/vulnerability/CVE-2017-1000071

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-1000071/
Summaries are generated and may contain mistakes; the official description above is the record.