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CVE-2023-34192: Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability

CVE-2023-34192 is rated critical with a CVSS v3.1 base score of 9.0 and affects Synacor Zimbra Collaboration Suite (ZCS). Per its scoring, it can be exploited over the network. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-02-25, which means exploitation in the wild has been observed.

Vulnerability description

Cross Site Scripting vulnerability in Zimbra ZCS v.8.8.15 allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.

Severity breakdown

CVSS v3.1 9.0: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: Low. A basic user account is enough.
  • User interaction: Required. A user must take an action, such as opening a file or following a link.
  • Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-79: Improper Neutralization of Input During Web Page Generation

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Affected products

  • Synacor Zimbra Collaboration Suite: 8.8.15; 8.8.15 p1; 8.8.15 p10; 8.8.15 p11; 8.8.15 p12; 8.8.15 p13; 8.8.15 p14; 8.8.15 p15; 8.8.15 p16; 8.8.15 p17; 8.8.15 p18; 8.8.15 p19

References