Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41 allows XSS in the Zimbra Classic Web Client.
- Published
- Jul 31, 2023
- Updated
- Jun 17, 2026
- EPSS
- 49.1% · 99th percentile
- CWE
- CWE-79
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Report tools
Action score
69
This week
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- CVSS
- 24 / 40 · 6.1 / 10
- CISA KEV
- 30 / 30 · Listed
- EPSS
- 15 / 30 · 49.1%
CISA SSVC decision
- Exploitation
- active
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Actively exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on Jul 27, 2023. That signals real attacks, not theory.
Remediation deadline for government agencies: Aug 17, 2023.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| synacor | zimbra collaboration suite | cpe:2.3:a:synacor:zimbra_collaboration_suite |
Using zimbra collaboration suite? Add it to your stack and be the first to know about CVEs like this one. (Email server)
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- synacor zimbra collaboration suite8.8.0 and later · before 8.8.15
- synacor zimbra collaboration suite8.8.15
Same product
synacor: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-45519The postjournal service in Zimbra Collaboration (ZCS) before 8.8.15 Patch 46, 9 before 9.0.0 Patch 41, 10 before 10.0.9, and 10.1 before 10.KEV99Now
- CVE-2019-9670mailboxd component in Synacor Zimbra Collaboration Suite 8.7.x before 8.7.11p10 has an XML External Entity injection (XXE) vulnerability, asKEV99Now
- CVE-2022-41352An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0.KEV98Now
- CVE-2022-37042Zimbra Collaboration Suite (ZCS) 8.8.15 and 9.0 has mboximport functionality that receives a ZIP archive and extracts files from it.KEV97Now
- CVE-2020-7796Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled.KEV94Now
- CVE-2023-34192Cross Site Scripting vulnerability in Zimbra ZCS v.8.8.15 allows a remote authenticated attacker to execute arbitrary code via a crafted scrKEV89Now
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Nuclei detection template ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Nuclei detection template | Nuclei template CVE-2023-37580 | — |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- CISA KEV-5 d
- Published
- TodaySep 29, 2026+1156 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
nvd-primary
Root cause
User content is inserted into the page as HTML. The browser interprets the content as code rather than data.
The bug in code
The whole CWE-79 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
commentEl.innerHTML = comment.body;Fixed
commentEl.textContent = comment.body;Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- www.openwall.com/lists/oss-security/2023/11/17/2
- wiki.zimbra.com/wiki/Security_Center
- wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-37580
Vendor advisories and official records. Exploit/PoC links are deliberately left out.