# CVE-2020-5283: XSS vulnerability in CVS show_subdir_lastmod support

> Attackers with commit privileges can inject malicious scripts via unsafe filenames in ViewVC when the show_subdir_lastmod feature is enabled.

- **Severity:** Low 3.1 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 3 Apr 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-xpxf-fvqv-7mfg, MGASA-2020-0221, UBUNTU-CVE-2020-5283, openSUSE-SU-2021:0084-1, openSUSE-SU-2021:0119-1, openSUSE-SU-2021:0123-1, openSUSE-SU-2021:0145-1

## What is CVE-2020-5283?

CVE-2020-5283 is a low-severity cross-site scripting vulnerability in viewvc, published on 3 Apr 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

ViewVC before versions 1.1.28 and 1.2.1 has a XSS vulnerability in CVS show_subdir_lastmod support. The impact of this vulnerability is mitigated by the need for an attacker to have commit privileges to a CVS repository exposed by an otherwise trusted ViewVC instance that also has the `show_subdir_lastmod` feature enabled. The attack vector involves files with unsafe names (names that, when embedded into an HTML stream, would cause the browser to run unwanted code), which themselves can be challenging to create. This vulnerability is patched in versions 1.2.1 and 1.1.28.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-80 (Improper Neutralization of Script-Related HTML Tags in a Web Page)

## Which versions are affected by CVE-2020-5283?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `viewvc` | SUSE:Package Hub 15 SP1 | All versions | 1.1.28-bp151.4.3.1 |
| `viewvc` | SUSE:Package Hub 15 SP2 | All versions | 1.1.28-bp152.4.3.1 |
| `viewvc` | openSUSE:Leap 15.1 | All versions | 1.1.28-lp151.3.3.1 |
| `viewvc` | openSUSE:Leap 15.2 | All versions | 1.1.28-lp152.4.3.1 |

Products: Viewvc Viewvc.

## How do I fix CVE-2020-5283?

Upgrade to a fixed version.

## Is CVE-2020-5283 being exploited?

There is no known exploitation of CVE-2020-5283 in the wild and no public exploit code.

## Other vulnerabilities in viewvc

- [CVE-2025-54141](https://insights.sbomify.com/CVE-2025-54141/): ViewVC's standalone server exposes arbitrary server filesystem content (high 7.5)
- [CVE-2010-0005](https://insights.sbomify.com/CVE-2010-0005/): Auth bypass in n/a (high 7.5)
- [CVE-2006-5442](https://insights.sbomify.com/CVE-2006-5442/): Cross-site scripting in n/a (medium 6.8)
- [CVE-2023-22456](https://insights.sbomify.com/CVE-2023-22456/): ViewVC XSS vulnerability in revision view changed paths (medium 6.1)
- [CVE-2008-4325](https://insights.sbomify.com/CVE-2008-4325/): Cross-site scripting in n/a (medium 5.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-5283 and fix it if it is affected.

What it is: CVE-2020-5283 is a low-severity cross-site scripting vulnerability in viewvc, published on 3 Apr 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-5283 in the wild and no public exploit code.

Affected product: viewvc. 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-2020-5283/ (Markdown: https://insights.sbomify.com/CVE-2020-5283/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-5283
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-5283
- OSV: https://osv.dev/vulnerability/CVE-2020-5283

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-5283/
Summaries are generated and may contain mistakes; the official description above is the record.