# CVE-2018-6882: Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS)

> Remote attackers can inject arbitrary web script or HTML via a Content-Location header in email attachments, potentially compromising user sessions.

- **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:** Yes, since 19 Apr 2022 (CISA KEV), used in ransomware
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 27 Mar 2018
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-3rrv-gxmq-5643

## What is CVE-2018-6882?

CVE-2018-6882 is a medium-severity cross-site scripting vulnerability in Synacor Zimbra Collaboration Suite, published on 27 Mar 2018. 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 ZmMailMsgView.getAttachmentLinkHtml function in Zimbra Collaboration Suite (ZCS) before 8.7 Patch 1 and 8.8.x before 8.8.7 might allow remote attackers to inject arbitrary web script or HTML via a Content-Location header in an email attachment.

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

## Which versions are affected by CVE-2018-6882?

It affects 1 product.


Products: Synacor Zimbra Collaboration Suite.

## How do I fix CVE-2018-6882?

No fix has been published for CVE-2018-6882 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 10 May 2022.

## Is CVE-2018-6882 being exploited?

Yes. Attackers have exploited CVE-2018-6882 in the wild since at least 19 Apr 2022, including in ransomware campaigns.

Public exploit code:

- Zimbra Collaboration Suite - Cross-site Scripting (nuclei): http/cves/2018/CVE-2018-6882.yaml

## Other vulnerabilities in Synacor Zimbra Collaboration Suite

- [CVE-2024-45519](https://insights.sbomify.com/CVE-2024-45519/): Synacor Zimbra Collaboration Suite (ZCS) Command Execution (critical 10.0, exploited in the wild)
- [CVE-2022-41352](https://insights.sbomify.com/CVE-2022-41352/): Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload (critical 9.8, exploited in the wild)
- [CVE-2022-37042](https://insights.sbomify.com/CVE-2022-37042/): Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2022-27924](https://insights.sbomify.com/CVE-2022-27924/): Synacor Zimbra Collaboration Suite (ZCS) Command Injection (critical 9.8, exploited in the wild)
- [CVE-2020-7796](https://insights.sbomify.com/CVE-2020-7796/): Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-6882 and fix it if it is affected.

What it is: CVE-2018-6882 is a medium-severity cross-site scripting vulnerability in Synacor Zimbra Collaboration Suite, published on 27 Mar 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: Yes. Attackers have exploited CVE-2018-6882 in the wild since at least 19 Apr 2022, including in ransomware campaigns.

Affected product: Synacor Zimbra Collaboration Suite. 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-2018-6882/ (Markdown: https://insights.sbomify.com/CVE-2018-6882/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-6882
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-6882
- OSV: https://osv.dev/vulnerability/CVE-2018-6882

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From sbomify Insights: https://insights.sbomify.com/CVE-2018-6882/
Summaries are generated and may contain mistakes; the official description above is the record.