Skip to content
Noroxi
CVE-2024-27443· NVD / CVE Program· CNA mitre

An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0.

An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. A Cross-Site Scripting (XSS) vulnerability exists in the CalendarInvite feature of the Zimbra webmail classic user interface, because of improper input validation in the handling of the calendar header. An attacker can exploit this via an email message containing a crafted calendar header with an embedded XSS payload. When a victim views this message in the Zimbra webmail classic interface, the payload is executed in the context of the victim's session, potentially leading to execution of arbitrary JavaScript code.

MediumCVSS 6.1 · v3.1KEVWeaponized No fix recorded
Published
Aug 12, 2024
Updated
Jun 17, 2026
EPSS
23.6% · 98th percentile
Follow this CVE

Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.

Report tools

JSON

Action score

61

This week

Don’t wait for the next maintenance window.

CVSS
24 / 40 · 6.1 / 10
CISA KEV
30 / 30 · Listed
EPSS
7 / 30 · 23.6%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on May 19, 2025. That signals real attacks, not theory.

Remediation deadline for government agencies: Jun 9, 2025.

Affected systems

VendorProduct
zimbracollaboration

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • zimbra collaboration10.0.0 and later · before 10.0.7
  • zimbra collaboration9.0.0

Same product

zimbra: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-45518An issue was discovered in Zimbra Collaboration (ZCS) 10.1.x before 10.1.1, 10.0.x before 10.0.9, 9.0.0 before Patch 41, and 8.8.15 before P
    41Plan
  • CVE-2022-32294Zimbra Collaboration Open Source 8.8.15 does not encrypt the initial-login randomly created password (from the "zmprove ca" command).
    40Plan
  • CVE-2021-35209An issue was discovered in ProxyServlet.java in the /proxy servlet in Zimbra Collaboration Suite 8.8 before 8.8.15 Patch 23 and 9.x before 9
    40Plan
  • CVE-2023-29382An issue in Zimbra Collaboration ZCS v.8.8.15 and v.9.0 allows an attacker to execute arbitrary code via the sfdc_preauth.jsp component.
    39Monitor
  • CVE-2023-29381An issue in Zimbra Collaboration (ZCS) v.8.8.15 and v.9.0 allows a remote attacker to escalate privileges and obtain sensitive information v
    39Monitor
  • CVE-2023-34193File Upload vulnerability in Zimbra ZCS 8.8.15 allows an authenticated privileged user to execute arbitrary code and obtain sensitive inform
    35Monitor

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.

Public exploit evidence
SourceKindDate
Nuclei detection templateNuclei template CVE-2024-27443 —

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.

  1. Published
  2. CISA KEV+280 d
  3. TodaySep 29, 2026+778 d
EPSS, last 120 days

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 researchers

Finders, 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.

  • CVE-2023-45206181 days apartAn issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0.
    24Monitor
  • CVE-2023-45207181 days apartAn issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0.
    24Monitor
  • CVE-2023-48432181 days apartAn issue was discovered in Zimbra Collaboration (ZCS) 8.8.15, 9.0, and 10.0.
    24Monitor
  • CVE-2023-50808181 days apartZimbra Collaboration before Kepler 9.0.0 Patch 38 GA allows DOM-based JavaScript injection in the Modern UI.
    24Monitor
  • CVE-2023-43102249 days apartAn issue was discovered in Zimbra Collaboration (ZCS) before 10.0.4.
    24Monitor
  • CVE-2023-43103249 days apartAn XSS issue was discovered in a web endpoint in Zimbra Collaboration (ZCS) before 10.0.4 via an unsanitized parameter.
    24Monitor

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 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
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.

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 help

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records