CVE-2025-38618

Description

From CVE.org

In the Linux kernel, the following vulnerability has been resolved: vsock: Do not allow binding to VMADDR_PORT_ANY It is possible for a vsock to autobind to VMADDR_PORT_ANY. This can cause a use-after-free when a connection is made to the bound socket. The socket returned by accept() also has port VMADDR_PORT_ANY but is not on the list of unbound sockets. Binding it will result in an extra refcount decrement similar to the one fixed in fcdd2242c023 (vsock: Keep the binding until socket destruction). Modify the check in __vsock_bind_connectible() to also prevent binding to VMADDR_PORT_ANY.

Statement

A logic flaw allowed AF_VSOCK sockets to be bound to VMADDR_PORT_ANY, which could leave accepted sockets in an inconsistent state and trigger a refcount mismatch, leading to a use-after-free in the vsock core. A local unprivileged program can reach this via normal socket APIs (bind/accept), causing a kernel crash (denial of service). The fix disallows binding to VMADDR_PORT_ANY in __vsock_bind_connectible(), preventing the erroneous lifecycle path.

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).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score6.27.87.8
Attack VectorLocalLocalLocal
Attack ComplexityLowLowLow
Privileges RequiredNoneLowLow
User InteractionNoneNoneNone
ScopeUnchangedUnchangedUnchanged
ConfidentialityNoneHighHigh
Integrity ImpactNoneHighHigh
Availability ImpactHighHighHigh

Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Understanding the Weakness (CWE)

Integrity

Technical Impact: Modify Memory

The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.

Availability

Technical Impact: DoS: Crash, Exit, or Restart

If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.

Confidentiality

Technical Impact: Read Memory

Read operations on freed memory can sometimes leak sensitive information instead of causing a crash

Integrity,Confidentiality,Availability

Technical Impact: Execute Unauthorized Code or Commands

If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.

Frequently Asked Questions

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