Linux: Double Free
CVE-2025-38699 is a high-severity double free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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. The record lists versions 684c92bb08a25ed3c0356bc7eb532ed5b19588dd, 9337c2affbaebe00b75fdf84ea0e2fcf93c140af, ba024d92564580bb90ec367248ace8efe16ce815 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.19% 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
- Update Linux to 684c92bb08a25ed3c0356bc7eb532ed5b19588dd or 9337c2affbaebe00b75fdf84ea0e2fcf93c140af or ba024d92564580bb90ec367248ace8efe16ce815 or 8e03dd9fadf76db5b9799583074a1a2a54f787f1, whichever matches your release line, or a later version.
- Update SIMATIC CN 4100 to V5.0 or a later version.
- Update Linux Kernel to 5.4.297 or 5.10.241 or 5.15.190 or 6.1.149, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 7725ccfda59715ecf8f99e3b520a0b84cc2ea79e up to, but not including, 684c92bb08a25ed3c0356bc7eb532ed5b19588dd; 7725ccfda59715ecf8f99e3b520a0b84cc2ea79e up to, but not including, 9337c2affbaebe00b75fdf84ea0e2fcf93c140af; 7725ccfda59715ecf8f99e3b520a0b84cc2ea79e up to, but not including, ba024d92564580bb90ec367248ace8efe16ce815; 7725ccfda59715ecf8f99e3b520a0b84cc2ea79e up to, but not including, 8e03dd9fadf76db5b9799583074a1a2a54f787f1; 7725ccfda59715ecf8f99e3b520a0b84cc2ea79e up to, but not including, 39cfe2c83146aad956318f866d0ee471b7a61fa5; 7725ccfda59715ecf8f99e3b520a0b84cc2ea79e up to, but not including, 13f613228cf3c96a038424cd97aa4d6aadc66294; 7725ccfda59715ecf8f99e3b520a0b84cc2ea79e up to, but not including, 8456f862cb95bcc3a831e1ba87c0c17068be0f3f; 7725ccfda59715ecf8f99e3b520a0b84cc2ea79e up to, but not including, 50d9bd48321038bd6e15af5a454bbcd180cf6f80; and 2 more ranges | 684c92bb08a25ed3c0356bc7eb532ed5b19588dd, 9337c2affbaebe00b75fdf84ea0e2fcf93c140af, ba024d92564580bb90ec367248ace8efe16ce815, 8e03dd9fadf76db5b9799583074a1a2a54f787f1, 39cfe2c83146aad956318f866d0ee471b7a61fa5, 13f613228cf3c96a038424cd97aa4d6aadc66294 |
| Siemens | SIMATIC CN 4100 | before V5.0 | V5.0 |
| Linux | Linux Kernel | 2.6.33 up to, but not including, 5.4.297; 5.5 up to, but not including, 5.10.241; 5.11 up to, but not including, 5.15.190; 5.16 up to, but not including, 6.1.149; 6.2 up to, but not including, 6.6.103; 6.7 up to, but not including, 6.12.43; 6.13 up to, but not including, 6.15.11; 6.16 up to, but not including, 6.16.2; and 1 more ranges | 5.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.43 |
| Debian | Debian Linux | 11.0 | Not stated |
Version data comes from the organisation that assigned the CVE. 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
- LowNo special conditions are needed; the attack works reliably.
- 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:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: scsi: bfa: Double-free fix When the bfad_im_probe() function fails during initialization, the memory pointed to by bfad->im is freed without setting bfad->im to NULL. Subsequently, during driver uninstallation, when the state machine enters the bfad_sm_stopping state and calls the bfad_im_probe_undo() function, it attempts to free the memory pointed to by bfad->im again, thereby triggering a double-free vulnerability. Set bfad->im to NULL if probing fails.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/13f613228cf3c96a038424cd97aa4d6aadc66294
- git.kernel.org/stable/c/39cfe2c83146aad956318f866d0ee471b7a61fa5
- git.kernel.org/stable/c/50d9bd48321038bd6e15af5a454bbcd180cf6f80
- git.kernel.org/stable/c/684c92bb08a25ed3c0356bc7eb532ed5b19588dd
- git.kernel.org/stable/c/8456f862cb95bcc3a831e1ba87c0c17068be0f3f
- git.kernel.org/stable/c/8e03dd9fadf76db5b9799583074a1a2a54f787f1
- git.kernel.org/stable/c/9337c2affbaebe00b75fdf84ea0e2fcf93c140af
- git.kernel.org/stable/c/add4c4850363d7c1b72e8fce9ccb21fdd2cf5dc9
- git.kernel.org/stable/c/ba024d92564580bb90ec367248ace8efe16ce815
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/10/msg00007.htmlThird Party Advisory
- lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlThird Party Advisory
Other references
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 8.6 High severity
- 7.2 High severity
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