# CVE-2019-1010263: Auth bypass in Perl Crypt::JWT

> Attackers can bypass authentication in Perl Crypt::JWT by crafting tokens with hmac(), requiring an upgrade to the fixed version.

- **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:** 17 Jul 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-54vx-xvq8-jh85, UBUNTU-CVE-2019-1010263

## What is CVE-2019-1010263?

CVE-2019-1010263 is a critical authentication bypass vulnerability in Perl Crypt::JWT, published on 17 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Perl Crypt::JWT prior to 0.023 is affected by: Incorrect Access Control. The impact is: allow attackers to bypass authentication by providing a token by crafting with hmac(). The component is: JWT.pm, line 614. The attack vector is: network connectivity. The fixed version is: after commit b98a59b42ded9f9e51b2560410106207c2152d6c.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2019-1010263?

It affects 1 product.


Products: Perl Crypt\ \.

## How do I fix CVE-2019-1010263?

No fix has been published for CVE-2019-1010263 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1010263 being exploited?

There is no known exploitation of CVE-2019-1010263 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1010263 and fix it if it is affected.

What it is: CVE-2019-1010263 is a critical authentication bypass vulnerability in Perl Crypt::JWT, published on 17 Jul 2019. 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-2019-1010263 in the wild and no public exploit code.

Affected product: Perl Crypt::JWT. 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-2019-1010263/ (Markdown: https://insights.sbomify.com/CVE-2019-1010263/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1010263
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1010263
- OSV: https://osv.dev/vulnerability/CVE-2019-1010263

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-1010263/
Summaries are generated and may contain mistakes; the official description above is the record.