Critical Windows Flaw in TeamViewer Remote Management Exposes SYSTEM-Level File Deletion Risk

Arabian Post

4 days ago

A newly disclosed flaw in TeamViewer's Remote Management tools for Windows allows attackers with local, unprivileged access to delete files with SYSTEM-level privileges, raising serious security concerns for organisations relying on the platform. Tracked as CVE‑2025‑36537, the vulnerability stems from incorrect permissions during MSI rollback operations and affects installations prior to version 15.67. TeamViewer issued a patch on 24 June 2025 and urges all users with Remote Management enabled to upgrade immediately.
The vulnerability only applies to the Backup, Monitoring and Patch Management modules—standard screen-sharing configurations without these features are not exposed to the flaw. An attacker must already have local access, but can exploit the issue by triggering MSI rollback to delete arbitrary files within the SYSTEM context. That broad privilege is generally reserved for the Windows operating system itself, and misuse could facilitate full privilege escalation, data destruction, or deployment of additional malware for more sophisticated compromises.
TeamViewer assigns the vulnerability a CVSS 3.1 score of 7.0, indicating a high-severity threat. While the firm reports no in-the-wild exploitation, the gravity of SYSTEM-level file deletion leaves little room for complacency. The oversight has been attributed to improper permission assignment of critical resources within MSI rollback logic—a well-known software mechanism for restoring system states when an installation or patch fails.
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The issue affects all prior versions of the TeamViewer Remote Management client for Windows before 15.67, including multiple supported legacy builds, as well as the Host variant for equivalent versions. TeamViewer's vendor bulletin TV‑2025‑1002 provides full version details and upgrade instructions.
Security specialists warn that SYSTEM-level deletion grants an attacker unprecedented control. As one analyst noted, 'deleting arbitrary files as SYSTEM could disrupt monitoring services, back up data or core OS files,' potentially undermining incident response and remediation. Exploiting the MSI rollback path means standard OS protections and antivirus defences are typically bypassed, leaving only the update itself as an immediate remedy.
Remote Management remains a strategic vector, as Backup, Monitoring and Patch Management are common across IT operations, particularly in enterprise and managed service provider environments. Many organisations update legacy systems via these modules, and any oversight in patch adoption or delayed upgrade could expose systems to compromise. Even if remote desktop access is limited, the vulnerability becomes critical once an attacker gains basic user-level entry—via phishing, credential stuffing, malicious USB, or physical infiltration.
Cross-referencing authoritative vulnerability feeds and TeamViewer's own disclosure confirms no public exploitation has been observed. However, multiple industry experts caution that no news of attacks does not equate to immunity. A patch rated 7.0 by CVSS typically indicates an attacker with moderate effort could gain full control—bringing the risk to par with vulnerabilities often weaponised by ransomware groups or espionage actors.
In addition to urging patch adoption, TeamViewer emphasises the necessity of defence-in-depth. Isolating tools with SYSTEM rights, limiting local user privileges, and enforcing network segmentation can reduce attack surface even if local access is achieved prior to remedy deployment. Security-conscious organisations are also encouraged to audit patch schedules, ensuring Remote Management modules are included in regular updates, not just the baseline client.
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The bug comes months after another high-severity issue—CVE‑2025‑0065—affecting TeamViewer clients in argument delimitation parsing, also linked to potential privilege escalation and patched in version 15.62. In early 2024, a separate flaw in patch and asset management components similarly underscored structural weaknesses in privilege management. The pattern highlights the complexity of permission flows in large-scale remote management platforms and the importance of rigorous validation and testing for privilege boundaries.
TeamViewer credits Giuliano Sanfins of SiDi, working via the Trend Micro Zero Day Initiative, for identifying and responsibly disclosing the issue. The collaboration demonstrates the role of external researchers and bug bounty frameworks in safeguarding complex enterprise tools before exploitation occurs.
Organisations using TeamViewer's Remote Management suite should prioritise deployment of version 15.67 or later across all Windows hosts. Administrators are advised to verify versions in service and host deployments, ensure no components are skipped, and monitor vendor security bulletins for further updates.
Enhanced monitoring of log files for MSI rollback events, combined with endpoint detection systems tuned for unusual file deletion patterns, can offer interim safeguards. Those unable to immediately upgrade should consider temporarily disabling Remote Management features until patching is confirmed.