CVE-2025-41259 in SWUpdate
Summary
by MITRE • 06/03/2026
SWUpdate before 2026.05 is affected by a time-of-check time-of-use (TOCTOU) race condition that allows local unprivileged attackers to escalate privileges to root or install untrusted contents using a signed update.
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Analysis
by VulDB Data Team • 06/05/2026
The vulnerability in SWUpdate versions prior to 2026.05 represents a critical time-of-check time-of-use race condition that fundamentally undermines the integrity of the software update mechanism. This flaw exists within the update process where the system performs a check for update validity and then subsequently uses the same update file without revalidating its integrity, creating a window of opportunity for malicious actors to manipulate the system. The race condition occurs when an unprivileged local user can exploit this temporal gap to replace a legitimate update file with a malicious one between the time the system validates the signature and the time it actually executes the update process. This vulnerability directly maps to CWE-367 which specifically addresses time-of-check to time-of-use race conditions, where the system state changes between the validation and execution phases.
The operational impact of this vulnerability extends far beyond simple privilege escalation as it provides attackers with complete control over the target system. An attacker with local user access can leverage this weakness to elevate privileges to root level, effectively gaining full system control without requiring any specialized tools or advanced exploitation techniques. The malicious update installation capability means that attackers can not only escalate privileges but also install arbitrary software, modify system binaries, or establish persistent backdoors. This represents a severe compromise of the update security model that is fundamental to maintaining system integrity. The vulnerability particularly affects systems that rely on SWUpdate for managing software versions and security patches, making it a prime target for attackers seeking to establish long-term presence on compromised systems.
From an adversarial perspective, this vulnerability aligns with several tactics described in the ATT&CK framework under privilege escalation and persistence techniques. The TOCTOU race condition enables attackers to perform malicious code injection during the update process, which falls under the category of "Modify System Image" and "Exploitation for Privilege Escalation" techniques. The ability to install untrusted contents through a signed update process also supports the ATT&CK tactic of "Execution" as attackers can leverage the legitimate update mechanism to run malicious payloads. Organizations using affected SWUpdate versions face significant risk as attackers can exploit this vulnerability to bypass traditional security controls, including signature verification and access restrictions. The vulnerability's local requirement means that attackers must first gain initial access to the system, but once achieved, the privilege escalation capability provides a powerful vector for further compromise.
Mitigation strategies for this vulnerability require immediate patching of SWUpdate to version 2026.05 or later where the race condition has been eliminated through proper synchronization mechanisms. System administrators should implement additional security controls including file integrity monitoring to detect unauthorized modifications to update files, enhanced access controls to limit local user privileges, and regular security audits of update processes. The fix should ensure that update files are validated at both the check and use phases, preventing the temporal gap that enables exploitation. Organizations should also consider implementing update process isolation, where update operations occur in secure environments that prevent manipulation by unprivileged users. Network segmentation and monitoring solutions should be deployed to detect anomalous update activities that might indicate exploitation attempts. The vulnerability highlights the critical importance of proper race condition handling in security-critical systems and reinforces the need for comprehensive security testing of update mechanisms.