# CVE-2021-35043: Cross-site Scripting in OWASP AntiSamy

> Attackers can execute arbitrary scripts via crafted HTML attributes in OWASP AntiSamy when using the HTML output serializer.

- **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:** Yes
- **Published:** 19 Jul 2021
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2021-35043, GHSA-9c8w-jrw3-q2c3, UBUNTU-CVE-2021-35043

## What is CVE-2021-35043?

CVE-2021-35043 is a medium-severity cross-site scripting vulnerability in Netapp Active Iq Unified Manager, published on 19 Jul 2021. 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

OWASP AntiSamy before 1.6.4 allows XSS via HTML attributes when using the HTML output serializer (XHTML is not affected). This was demonstrated by a javascript: URL with &#00058 as the replacement for the : character.

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

## Which versions are affected by CVE-2021-35043?

2 open source packages ship an affected version, including org.owasp.antisamy:antisamy. It affects 11 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.owasp.antisamy:antisamy` | Maven | From 1.5.7 | 1.6.4 |
| `org.owasp.antisamy:antisamy` | Maven | From 1.5.7 | 1.6.4 |

Products: Antisamy Project Antisamy, Netapp Active Iq Unified Manager, Oracle Banking Enterprise Default Management, Oracle Banking Enterprise Default Managment, Oracle Banking Party Management, Oracle Banking Platform, Oracle Insurance Policy Administration, Oracle Middleware Common Libraries and Tools, Oracle Retail Back Office, Oracle Retail Central Office, Oracle Retail Returns Management.

## How do I fix CVE-2021-35043?

Upgrade org.owasp.antisamy:antisamy to 1.6.4 or later.

## Is CVE-2021-35043 being exploited?

There is no known exploitation of CVE-2021-35043 in the wild and no public exploit code.

## Other vulnerabilities in Netapp Active Iq Unified Manager

- [CVE-2022-28366](https://insights.sbomify.com/CVE-2022-28366/): Denial of service in HtmlUnit-Neko (high 7.5)
- [CVE-2024-23635](https://insights.sbomify.com/CVE-2024-23635/): AntiSamy malicious input can provoke XSS when preserving comments (medium 6.1)
- [CVE-2023-43643](https://insights.sbomify.com/CVE-2023-43643/): mXSS in AntiSamy (medium 6.1)
- [CVE-2022-28367](https://insights.sbomify.com/CVE-2022-28367/): Cross-site Scripting in OWASP AntiSamy (medium 6.1)
- [CVE-2022-29577](https://insights.sbomify.com/CVE-2022-29577/): Cross-site Scripting in OWASP AntiSamy (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-35043 and fix it if it is affected.

What it is: CVE-2021-35043 is a medium-severity cross-site scripting vulnerability in Netapp Active Iq Unified Manager, published on 19 Jul 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-35043 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.owasp.antisamy:antisamy (Maven): affected from 1.5.7; fixed in 1.6.4
- org.owasp.antisamy:antisamy (Maven): affected from 1.5.7; fixed in 1.6.4

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-2021-35043/ (Markdown: https://insights.sbomify.com/CVE-2021-35043/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-35043
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-35043
- OSV: https://osv.dev/vulnerability/CVE-2021-35043

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-35043/
Summaries are generated and may contain mistakes; the official description above is the record.