# CVE-2021-33479: Memory corruption in gocr

> A stack-based buffer overflow in gocr allows attackers to execute arbitrary code or cause denial of service via crafted input.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 17 Nov 2021
- **Updated:** 18 Nov 2024
- **Also known as:** DEBIAN-CVE-2021-33479, GHSA-cfqc-x96c-8xxg, UBUNTU-CVE-2021-33479

## What is CVE-2021-33479?

CVE-2021-33479 is a high-severity memory corruption vulnerability in gocr, published on 17 Nov 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A stack-based buffer overflow vulnerability was discovered in gocr through 0.53-20200802 in measure_pitch() in pgm2asc.c.

Weakness: CWE-787 (Out-of-bounds Write), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2021-33479?

It affects 1 product.


Products: Optical Character Recognition Project Optical Character Recognition.

## How do I fix CVE-2021-33479?

No fix has been published for CVE-2021-33479 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-33479 being exploited?

There is no known exploitation of CVE-2021-33479 in the wild and no public exploit code.

## Other vulnerabilities in gocr

- [CVE-2005-1141](https://insights.sbomify.com/CVE-2005-1141/): Integer overflow in n/a (critical 9.8)
- [CVE-2021-33481](https://insights.sbomify.com/CVE-2021-33481/): Memory corruption in gocr (high 7.8)
- [CVE-2021-33480](https://insights.sbomify.com/CVE-2021-33480/): Use after free in gocr (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-33479 and fix it if it is affected.

What it is: CVE-2021-33479 is a high-severity memory corruption vulnerability in gocr, published on 17 Nov 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-33479 in the wild and no public exploit code.

Affected product: gocr. 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-2021-33479/ (Markdown: https://insights.sbomify.com/CVE-2021-33479/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-33479
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-33479
- OSV: https://osv.dev/vulnerability/CVE-2021-33479

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-33479/
Summaries are generated and may contain mistakes; the official description above is the record.