# CVE-2020-18831: Memory corruption in n/a

> Remote attackers can cause denial of service and other impacts via crafted files due to a buffer overflow in the Exiv2 image library.

- **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:** Yes
- **Published:** 22 Aug 2023
- **Updated:** 4 Oct 2024
- **Also known as:** DEBIAN-CVE-2020-18831, GHSA-xwp4-phw7-5mfh, PYSEC-2023-150

## What is CVE-2020-18831?

CVE-2020-18831 is a high-severity memory corruption vulnerability in Exiv2 Exiv2, published on 22 Aug 2023. 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

Buffer Overflow vulnerability in tEXtToDataBuf function in pngimage.cpp in Exiv2 0.27.1 allows remote attackers to cause a denial of service and other unspecified impacts via use of crafted file.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2020-18831?

1 open source package ship an affected version, including exiv2. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `exiv2` | PyPI | All versions | None |

Products: Exiv2 Exiv2.

## How do I fix CVE-2020-18831?

Upgrade to a fixed version.

## Is CVE-2020-18831 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-18831 exists.

## Other vulnerabilities in Exiv2 Exiv2

- [CVE-2023-44398](https://insights.sbomify.com/CVE-2023-44398/): Out-of-bounds write in exiv2 (high 8.8)
- [CVE-2019-9143](https://insights.sbomify.com/CVE-2019-9143/): Denial of service in n/a (high 8.8)
- [CVE-2019-9144](https://insights.sbomify.com/CVE-2019-9144/): Denial of service in n/a (high 8.8)
- [CVE-2018-14046](https://insights.sbomify.com/CVE-2018-14046/): Memory corruption in n/a (high 8.8)
- [CVE-2017-12955](https://insights.sbomify.com/CVE-2017-12955/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-18831 and fix it if it is affected.

What it is: CVE-2020-18831 is a high-severity memory corruption vulnerability in Exiv2 Exiv2, published on 22 Aug 2023. 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-18831 exists.

Affected packages and fixed versions:
- exiv2 (PyPI): affected all versions; no fix listed

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-2020-18831/ (Markdown: https://insights.sbomify.com/CVE-2020-18831/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-18831
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-18831
- OSV: https://osv.dev/vulnerability/CVE-2020-18831

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-18831/
Summaries are generated and may contain mistakes; the official description above is the record.