CVE-2025-38718
Description
A flaw use of uninitialized memory (uncontrolled and invisible by attacker) in the Linux kernel SCTP transport protocol was found in the way user triggers malicious SCTP packets. A remote user could use this flaw to crash the system. The bug actual only for systems where SCTP protocol being enabled and used.
Statement
A flaw in the SCTP receive path failed to linearize cloned GSO sk_buffs before accessing fraglists, leading to reads of uninitialized memory as reported by KMSAN. An attacker sending SCTP traffic can trigger incorrect processing and potentially cause a kernel denial of service on the target under specific RX conditions. Stream Control Transmission Protocol (SCTP) is a transport-layer protocol (like TCP or UDP) primarily used in telecom signaling and some specialized applications. On most Linux systems it is disabled by default, and remote connectivity is only possible if SCTP support is enabled and listening services are configured (commonly using the IANA-assigned port 2905/tcp for M3UA or other protocol-specific ports). Therefore, the vulnerability is only exploitable when SCTP is enabled and reachable on the target system. Although KMSAN reports this issue as use of uninitialized memory (which deterministically crashes with KMSAN enabled), on production kernels the impact is still availability-related.
Mitigation
To mitigate this issue, prevent module sctp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
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 | 7.5 | 7.8 | 7.8 |
| Attack Vector | Network | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | High | High |
| Integrity Impact | None | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:N/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)
Other
Technical Impact: Other
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