#VU106805 Input validation error in Linux kernel - CVE-2025-21921
Vulnerability identifier: #VU106805
Vulnerability risk: Low
CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID:
CWE-ID:
CWE-20
Exploitation vector: Local
Exploit availability: No
Vulnerable software:
Linux kernel
Operating systems & Components /
Operating system
Vendor: Linux Foundation
Description
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to improper input validation within the strset_prepare_data() function in net/ethtool/strset.c, within the stats_prepare_data() function in net/ethtool/stats.c, within the pse_prepare_data() and ethnl_set_pse() functions in net/ethtool/pse-pd.c, within the plca_get_cfg_prepare_data(), ethnl_set_plca() and plca_get_status_prepare_data() functions in net/ethtool/plca.c, within the ethnl_phy_parse_request() function in net/ethtool/phy.c, within the ethnl_parse_header_dev_get() and ethnl_req_get_phydev() functions in net/ethtool/netlink.c, within the linkstate_prepare_data() function in net/ethtool/linkstate.c, within the ethnl_act_cable_test() and ethnl_act_cable_test_tdr() functions in net/ethtool/cabletest.c. A local user can perform a denial of service (DoS) attack.
Mitigation
Install update from vendor's website.
Vulnerable software versions
Linux kernel: 6.12, 6.12.1, 6.12.2, 6.12.3, 6.12.4, 6.12.5, 6.12.6, 6.12.7, 6.12.8, 6.12.9, 6.12.10, 6.12.11, 6.12.12, 6.12.13, 6.12.14, 6.12.15, 6.12.16, 6.12.17, 6.12.18
External links
https://git.kernel.org/stable/c/1f458fa42c29144cef280e05bc49fc21b873d897
https://git.kernel.org/stable/c/637399bf7e77797811adf340090b561a8f9d1213
https://git.kernel.org/stable/c/639c70352958735addbba5ae7dd65985da96e061
https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.19
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
