Junglewise Threat Intelligence

CVE-2025-21787: Linux Kernel uninitialized memory read in team driver

CVE-2025-21787 · Severity: medium · CVSS 5.5 · Published 2025-02-27

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's network teaming driver could allow a local user to cause a system crash. The issue stems from improper validation of text-based configuration options, which can lead to the system reading uninitialized memory. This primarily impacts the availability of the affected system.

Technical details

A use of uninitialized resource (CWE-908) exists in the Linux kernel's team driver (drivers/net/team). The vulnerability occurs in team_nl_options_set_doit (or team_nl_cmd_options_set in some versions) when processing TEAM_OPTION_TYPE_STRING. The driver failed to ensure that user-provided string data was properly null-terminated before passing it to functions like vsnprintf. A local attacker with sufficient privileges to modify network team options can exploit this via Netlink to trigger an uninitialized value read, potentially leading to a kernel panic or denial of service. Patches have been released across multiple stable kernel branches to enforce null-byte validation.

Affected products

  • Linux Linux Kernel 3.3 to 6.1.129, 6.2 to 6.6.79, 6.7 to 6.12.16, 6.13 to 6.13.4

Timeline

  • 2025-02-12: patched: Initial patch authored by Eric Dumazet
  • 2025-02-27: disclosed: CVE published

References

Related threats