Ec2007 Kernel: Time-of-check Time-of-use (TOCTOU) Race Condition
CVE-2025-61037 is a high-severity time-of-check time-of-use (TOCTOU) race condition vulnerability in Ec2007 Kernel from Sevencs, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Ec2007 Kernel versions: 5.22. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Ec2007 Kernel you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Sevencs | Ec2007 Kernel | 5.22 | Not stated |
| Sevencs | Orca G2 | 2.0.1.35 | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
A local privilege escalation vulnerability exists in SevenCs ORCA G2 2.0.1.35 (EC2007 Kernel v5.22). The flaw is a Time-of-Check Time-of-Use (TOCTOU) race condition in the license management logic. The regService process, which runs with SYSTEM privileges, creates a fixed directory and writes files without verifying whether the path is an NTFS reparse point. By exploiting this race condition, an attacker can replace the target directory with a junction pointing to a user-controlled path. This causes the SYSTEM-level process to drop binaries in a location fully controlled by the attacker, allowing arbitrary code execution with SYSTEM privileges. The vulnerability can be exploited by any standard user with only a single UAC confirmation, making it highly practical and dangerous in real-world environments.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Time-of-check Time-of-use (TOCTOU) Race Condition
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
How developers prevent this class of flaw
- The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
- When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
- Limit the interleaving of operations on files from multiple processes.
More Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities (CWE-367)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- gist.github.com/jc0818/233462416579661e4e2795f96457a6bfExploit, Third Party Advisory
Other vulnerabilities in Ec2007 Kernel
- 7.8 High severity
Recent Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities
- 7.4 High severity
- 7.5 High severity
- 7.5 High severity
- 7.4 High severity
- 10.0 Critical severity
- 7.0 High severity
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