CVE-2018-6882 — zm-build
MEDIUMCVE-2018-6882 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-04-19) and has been used in ransomware campaigns — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-04-19 — including use in ransomware campaigns. Federal agencies were required to remediate by 2022-05-10.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2018-6882.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2018-6882 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
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.
Affected Products
zimbra collaboration suitesynacorResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachm…
Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachm…
Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachm…
Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachm…
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2018-6882 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
How to detect CVE-2018-6882
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2018-6882 -u https://target- Template
- Zimbra Collaboration Suite - Cross-site Scripting
- Severity
- medium
- Impact
- Attackers can execute arbitrary JavaScript in victims' browsers via malicious email attachments, potentially stealing session cookies, credentials, or accessing sensitive email data.
- Remediation
- Upgrade to Zimbra Collaboration Suite version 8.7 Patch 1 or 8.8.7 or later.
Template by ProjectDiscovery nuclei-templates (Sourabh-Sahu), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2018-6882 in your dependencies?
Find it across , including transitive dependencies.