# CVE-2021-42551: Reflected XSS in NetBiblio WebOPAC search functionality

> An unauthenticated attacker can execute arbitrary scripts in a victim's browser via the search functionality of NetBiblio WebOPAC.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 14 Jan 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-hrpc-fm5f-rg4v

## What is CVE-2021-42551?

CVE-2021-42551 is a medium-severity cross-site scripting vulnerability in AlCoda NetBiblio WebOPAC, published on 14 Jan 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Cross-site Scripting (XSS) vulnerability in the search functionality of AlCoda NetBiblio WebOPAC allows an unauthenticated user to craft a reflected Cross-Site Scripting attack. This issue affects: AlCoda NetBiblio WebOPAC versions prior to 4.0.0.320; versions later than 4.0.0.328. This issue does not affect: AlCoda NetBiblio WebOPAC version 4.0.0.335 and later versions.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-42551?

It affects 1 product.


Products: Alcoda Netbiblio.

## How do I fix CVE-2021-42551?

No fix has been published for CVE-2021-42551 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42551 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-42551 exists.

Public exploit code:

- NetBiblio WebOPAC - Cross-Site Scripting (nuclei): http/cves/2021/CVE-2021-42551.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42551 and fix it if it is affected.

What it is: CVE-2021-42551 is a medium-severity cross-site scripting vulnerability in AlCoda NetBiblio WebOPAC, published on 14 Jan 2022. An attacker can exploit it over the internet without logging in, 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-2021-42551 exists.

Affected product: AlCoda NetBiblio WebOPAC. 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-2021-42551/ (Markdown: https://insights.sbomify.com/CVE-2021-42551/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42551
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42551
- OSV: https://osv.dev/vulnerability/CVE-2021-42551

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42551/
Summaries are generated and may contain mistakes; the official description above is the record.