CVE-2025-40186
Description
A flaw was found in the Linux kernel. A local attacker with low privileges could exploit a memory corruption vulnerability, specifically a use-after-free and double-free, within the TCP Fast Open (TFO) socket processing. This occurs when a listener is closed while a TFO socket is being processed in tcp_conn_request(). Successful exploitation could lead to a kernel panic, resulting in a Denial of Service (DoS), or potentially allow the attacker to execute arbitrary code with elevated privileges.
Statement
This vulnerability is rated Important for Red Hat Enterprise Linux. A local attacker with low privileges can exploit a use-after-free and double-free flaw in the Linux kernel's TCP Fast Open (TFO) implementation. This could lead to a kernel panic, resulting in a Denial of Service, or potentially allow for privilege escalation. This affects Red Hat Enterprise Linux 7, 8, 9 (up to 9.7.z), and 10 (up to 10.1.z).
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7 | N/A | 8.1 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Memory
If the released resource is subsequently reused or reallocated, then a read operation on the original resource might access sensitive data that is associated with a different user or entity.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
When the resource is released, the software might modify some of its structure, or close associated channels (such as a file descriptor). When the software later accesses the resource as if it is valid, the resource might not be in an expected state, leading to resultant errors that may lead to a crash.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands; Modify Application Data; Modify Memory
When the resource is released, the software might modify some of its structure. This might affect logic in the sections of code that still assume the resource is active. If the released resource is related to memory and is used in a function call, or points to unexpected data in a write operation, then code execution may be possible upon subsequent accesses.
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