CVE-2025-21742
CVE-2025-21742 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.
Key facts
- Severity: High (CVSS 3.x base score 7.1)
- EPSS exploit prediction: 0% (11th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-5173
- Weakness: CWE-125
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: usbnet: ipheth: use static NDP16 location in URB Original code allowed for the start of NDP16 to be anywhere within the URB based on the `wNdpIndex` value in NTH16. Only the start position of NDP16 was checked, so it was possible for even the fixed-length part of NDP16 to extend past the end of URB, leading to an out-of-bounds read. On iOS devices, the NDP16 header always directly follows NTH16. Rely on and check for this specific format. This, along with NCM-specific minimal URB length check that already exists, will ensure that the fixed-length part of NDP16 plus a set amount of DPEs fit within the URB. Note that this commit alone does not fully address the OoB read. The limit on the amount of DPEs needs to be enforced separately.
Frequently asked questions
- What is CVE-2025-21742?
- In the Linux kernel, the following vulnerability has been resolved: usbnet: ipheth: use static NDP16 location in URB Original code allowed for the start of NDP16 to be anywhere within the URB based on the `wNdpIndex` value in NTH16. Only the start position of NDP16 was checked, so it was possible for even the fixed-length part of NDP16 to extend past the end of URB, leading to an out-of-bounds read. On iOS devices, the NDP16 header always directly follows NTH16. Rely on and check for this specific format. This, along with NCM-specific minimal URB length check that already exists, will ensure that the fixed-length part of NDP16 plus a set amount of DPEs fit within the URB. Note that this commit alone does not fully address the OoB read. The limit on the amount of DPEs needs to be enforced separately.
- How severe is CVE-2025-21742?
- CVE-2025-21742 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
- Is CVE-2025-21742 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2025-21742?
- CVE-2025-21742 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2025-21742?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2025-21742 have an EU (EUVD) identifier?
- Yes. CVE-2025-21742 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-5173.
- When was CVE-2025-21742 published?
- CVE-2025-21742 was published on 2025-02-27 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/2b619445dcb6dab97d8ed033fb57225aca1288c4
- https://git.kernel.org/stable/c/86586dcb75cb8fd062a518aca8ee667938b91efb
- https://git.kernel.org/stable/c/8fb062178e1ce180e2cfdc9abc83a1b9fea381ca
- https://git.kernel.org/stable/c/cf1ac7f7cf601ac31d1580559c002b5e37b733b7
Affected products (1)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
More vulnerabilities in Linux Linux Kernel
- CVE-2023-2163 — Critical (CVSS 10.0): Incorrect verifier pruning in BPF in Linux Kernel >=5.4 leads to unsafe code paths being incorrectly marked as safe,…
- CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
- CVE-2015-1421 — Critical (CVSS 10.0): Use-after-free vulnerability in the sctp_assoc_update function in net/sctp/associola.c in the Linux kernel before…
- CVE-2014-2523 — Critical (CVSS 10.0): net/netfilter/nf_conntrack_proto_dccp.c in the Linux kernel through 3.13.6 uses a DCCP header pointer incorrectly,…
- CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
- CVE-2010-2521 — Critical (CVSS 10.0): Multiple buffer overflows in fs/nfsd/nfs4xdr.c in the XDR implementation in the NFS server in the Linux kernel before…
All CVEs affecting Linux Linux Kernel →
Other CWE-125 (Out-of-bounds Read) vulnerabilities
- CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
- CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
- CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
- CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
- CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
- CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…