CVE-2025-27915
CVE-2025-27915
In short
A vulnerability in Zimbra email allows attackers to embed malicious code in calendar files (ICS) that executes when a user opens an email containing them. This lets the attacker run unwanted actions in the victim's email account, like redirecting messages or stealing data.
Technical detail
Stored XSS vulnerability in Zimbra Collaboration 9.0-10.1 Classic Web Client affecting ICS file parsing; insufficient HTML sanitization allows JavaScript execution via ontoggle event in details tags when users view malicious calendar entries, enabling session hijacking and unauthorized account operations such as email filter manipulation and data exfiltration.
Summary generated and translated by AI from the official description.
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:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Affected products
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Talk to TrueHacking →References
https://strikeready.com/blog/0day-ics-attack-in-the-wild/https://wiki.zimbra.com/wiki/Security_Centerhttps://wiki.zimbra.com/wiki/Zimbra_Releases/10.0.13#Security_Fixeshttps://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.5#Security_Fixeshttps://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P44#Security_Fixeshttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-27915