CVE-2025-27915
KEVMEDIUM 5.4EPSS 4.1%
An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an e-mail message containing a malicious ICS entry, its embedded JavaScript executes via an ontoggle event inside a <details> tag. This allows an attacker to run arbitrary JavaScript within the victim's session, potentially leading to unauthorized actions such as setting e-mail filters to redirect messages to an attacker-controlled address. As a result, an attacker can perform unauthorized actions on the victim's account, including e-mail redirection and data exfiltration.
- CVSS v3.1 CNA
- 5.4 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - EPSS
- 4.06% chance of exploitation in the next 30 days, 91st percentile
- CISA KEV
- added 2025-10-07
- Nuclei
- medium · CWE-79
- Published
- 2025-03-12
- Updated
- 2026-02-26
Proof-of-concept exploits (1)
- alsyundawy/eradicate-zimbra-malware2★ · 2026-09-21
Nuclei templates (1)
Security advisories
- https://strikeready.com/blog/0day-ics-attack-in-the-wild
- https://wiki.zimbra.com/wiki/Security_Center
- https://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.13#Security_Fixes
- https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.5#Security_Fixes
- https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P44#Security_Fixes