CVE-2025-40002
Vulnerability Scoring
Status: Awaiting Analysis
Last updated: 🕢 21 Oct 2025, 19:31 UTC
Originally published on: 🕗 18 Oct 2025, 08:15 UTC
Time between publication and last update: 3 days
CVSS Release:
CVE-2025-40002: In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Fix use-after-free in tb_dp_dprx_work The original code relies on cancel_delayed_work() in tb_dp_dprx_stop(), which does not ensure that the delayed work item tunnel->dprx_work has fully completed if it was already running. This leads to use-after-free scenarios where tb_tunnel is deallocated by tb_tunnel_put(), while tunnel->dprx_work remains active and attempts to dereference tb_tunnel in tb_dp_dprx_work(). A typical race condition is illustrated below: CPU 0 | CPU 1 tb_dp_tunnel_active() | tb_deactivate_and_free_tunnel()| tb_dp_dprx_start() tb_tunnel_deactivate() | queue_delayed_work() tb_dp_activate() | tb_dp_dprx_stop() | tb_dp_dprx_work() //delayed worker cancel_delayed_work() | tb_tunnel_put(tunnel); | | tunnel = container_of(...); //UAF | tunnel-> //UAF Replacing cancel_delayed_work() with cancel_delayed_work_sync() is not feasible as it would introduce a deadlock: both tb_dp_dprx_work() and the cleanup path acquire tb->lock, and cancel_delayed_work_sync() would wait indefinitely for the work item that cannot proceed. Instead, implement proper reference counting: - If cancel_delayed_work() returns true (work is pending), we release the reference in the stop function. - If it returns false (work is executing or already completed), the reference is released in delayed work function itself. This ensures the tb_tunnel remains valid during work item execution while preventing memory leaks. This bug was found by static analysis.
The exploitability of CVE-2025-40002 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
No exploitability data is available for CVE-2025-40002.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2025-40002, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2025-40002, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
Unknown
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