CVE-2025-68645
Synacor Zimbra Collaboration Suite 10.0.0 – 10.0.18
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSummary
CVE-2025-68645 is a high-severity PHP Remote File Inclusion (CWE-98) vulnerability in Synacor Zimbra Collaboration Suite. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-68645 is a Local File Inclusion (LFI) vulnerability, mapped to CWE-98, affecting the Webmail Classic UI in Zimbra Collaboration Suite (ZCS) versions 10.0 and 10.1. The flaw arises from improper handling of user-supplied request parameters within the RestFilter servlet, enabling attackers to manipulate internal request dispatching. Published on 2025-12-22, it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), reflecting high potential impact across confidentiality, integrity, and availability.
An unauthenticated remote attacker can exploit the vulnerability by crafting requests to the /h/rest endpoint, tricking a user into interacting with a malicious payload—such as clicking a link in a phishing email. Successful exploitation allows inclusion of arbitrary files from the WebRoot directory, potentially exposing sensitive configuration data, source code, or other server files, depending on directory contents and permissions.
Zimbra's Security Center wiki and Responsible Disclosure Policy provide relevant advisory details on patches and mitigation steps. The vulnerability also appears in CISA's Known Exploited Vulnerabilities catalog, signaling real-world exploitation by threat actors. Security practitioners should prioritize patching affected ZCS instances and monitor for anomalous /h/rest requests.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-204719
Vulnerability Data
A Local File Inclusion (LFI) vulnerability exists in the Webmail Classic UI of Zimbra Collaboration (ZCS) 10.0 and 10.1 because of improper handling of user-supplied request parameters in the RestFilter servlet. An unauthenticated remote attacker can craft requests to the…
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/h/rest endpoint to influence internal request dispatching, allowing inclusion of arbitrary files from the WebRoot directory.
- CWE(s)
- KEV Date Added
- 22 January 2026
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and static analysis can discover missing filename restrictions before deployment.
Validating all inputs before they reach include/require statements directly stops untrusted filenames from being used.
Enforcing access authorizations on resources limits what an included file can reach even if a bad name is supplied.
Information-flow rules can block the loading of external or unauthorized files into the PHP process.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices such as input validation and allow-listing of include paths directly prevent the weakness.
Hardened runtime configuration (e.g., allow_url_include=off) directly blocks RFI even if code is flawed.
Execution restrictions can prevent the remote payload from running, while eliminating the weakness reduces the need for such controls.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect RFI but does not prevent the weakness by itself.
Secure development lifecycle mandates input validation and safe include/require patterns that directly prevent remote file inclusion.
Application security requirements explicitly call for controls against injection and unsafe file operations.
Secure architecture principles reduce attack surface but do not specifically address dynamic file inclusion.
Secure coding standards directly require whitelisting and sanitization of filenames used in include/require statements.
Information access restriction limits what files can be read but does not address dynamic inclusion logic.