# CVE-2017-2773: Auth bypass in PCF Elastic Runtime

> Attackers can impersonate users due to incomplete JWT validation, leading to unauthorized access in PCF Elastic Runtime.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/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:** No
- **Published:** 13 Jun 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-q8g2-5223-5rmm

## What is CVE-2017-2773?

CVE-2017-2773 is a critical authentication bypass vulnerability in PCF Elastic Runtime, published on 13 Jun 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Pivotal PCF Elastic Runtime 1.6.x versions prior to 1.6.60, 1.7.x versions prior to 1.7.41, 1.8.x versions prior to 1.8.23, and 1.9.x versions prior to 1.9.1. Incomplete validation logic in JSON Web Token (JWT) libraries can allow unprivileged attackers to impersonate other users in multiple components included in PCF Elastic Runtime, aka an "Unauthenticated JWT signing algorithm in multiple components" issue.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-2773?

It affects 1 product.


Products: Pivotal Software Cloud Foundry Elastic Runtime.

## How do I fix CVE-2017-2773?

No fix has been published for CVE-2017-2773 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-2773 being exploited?

There is no known exploitation of CVE-2017-2773 in the wild and no public exploit code.

## Other vulnerabilities in PCF Elastic Runtime

- [CVE-2017-4955](https://insights.sbomify.com/CVE-2017-4955/): Information disclosure in PCF Elastic Runtime (critical 9.8)
- [CVE-2017-4959](https://insights.sbomify.com/CVE-2017-4959/): Auth bypass in PCF Elastic Runtime (high 8.8)
- [CVE-2016-6657](https://insights.sbomify.com/CVE-2016-6657/): Open redirect in PCF Elastic Runtime 1.8.x versions prior to 1.8.12 and PCF Ops Manager 1.7.x versions prior to 1.7.18 and 1.8.x versions prior to 1.8.10 (high 7.4)
- [CVE-2016-0896](https://insights.sbomify.com/CVE-2016-0896/): Security feature bypass in n/a (high 7.3)
- [CVE-2016-0926](https://insights.sbomify.com/CVE-2016-0926/): Cross-site scripting in n/a (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-2773 and fix it if it is affected.

What it is: CVE-2017-2773 is a critical authentication bypass vulnerability in PCF Elastic Runtime, published on 13 Jun 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-2017-2773 in the wild and no public exploit code.

Affected product: PCF Elastic Runtime. 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-2017-2773/ (Markdown: https://insights.sbomify.com/CVE-2017-2773/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-2773
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-2773
- OSV: https://osv.dev/vulnerability/CVE-2017-2773

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-2773/
Summaries are generated and may contain mistakes; the official description above is the record.