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CVE Record

CVE-2025-21808: net: xdp: Disallow attaching device-bound programs in generic mode

In the Linux kernel, the following vulnerability has been resolved: net: xdp: Disallow attaching device-bound programs in generic mode Device-bound programs are used to support RX metadata kfuncs. These kfuncs are driver-specific and rely on the driver context to read the metadata. This means they can't work in generic XDP mode. However, there is no check to disallow such programs from being attached in generic mode, in which case the metadata kfuncs will be called in an invalid context, leading to crashes. Fix this by adding a check to disallow attaching device-bound programs in generic mode.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue can let an invalid XDP/eBPF program attachment path crash the system. The business risk is service disruption on affected Linux hosts, especially where advanced packet-processing features are used. The sources do not provide a CVSS score, attacker prerequisites, or evidence of active exploitation.

Executive priority

Treat this as a reliability and availability concern for Linux networking workloads. Prioritize patch validation for systems using XDP/eBPF or custom packet processing, while monitoring vendor advisories because severity and exploitation evidence are not supplied.

Technical view

Device-bound XDP programs support driver-specific RX metadata kfuncs. The kernel allowed those programs to attach in generic XDP mode, where the required driver context is unavailable. Calling the metadata kfuncs in that invalid context can lead to crashes. The fix disallows attaching device-bound programs in generic mode.

Likely exposure

Exposure is most plausible on Linux systems using XDP/eBPF networking features, RX metadata kfuncs, or generic XDP mode. The bundle lists Linux kernel versions including 6.3 and fixed stable references, but does not map this cleanly to distro packages or enterprise kernel backports.

Exploitation context

The source bundle does not show CISA KEV listing, public exploitation, exploit code, or attacker prerequisites. Practical triggerability likely depends on the ability to load or attach XDP/eBPF programs and on affected kernel behavior, but the supplied sources do not define that access model.

Researcher notes

The key behavior is an attachment validation gap between device-bound XDP programs and generic XDP mode. Analysis should focus on kernel versions carrying the vulnerable path, distro backports, and whether local policy permits loading or attaching eBPF/XDP programs.

Mitigation direction

  • Update to a vendor kernel containing the referenced stable fixes.
  • Check Linux distribution advisories for backported fixes.
  • Avoid attaching device-bound XDP programs in generic mode on unpatched systems.
  • Prioritize hosts that run custom eBPF, XDP, or packet-processing workloads.
  • Track vendor guidance if no package fix is available yet.

Validation and detection

  • Inventory Linux kernel versions across exposed and production hosts.
  • Confirm whether distro kernels include the referenced stable commits.
  • Identify systems using XDP, eBPF, or RX metadata kfuncs.
  • Review change records for generic XDP mode usage.
  • Validate patched kernels in staging before broad rollout.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2025-21808 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
5Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux2b3486bc2d237ec345b3942b7be5deabf8c8fed1, 2b3486bc2d237ec345b3942b7be5deabf8c8fed1, 2b3486bc2d237ec345b3942b7be5deabf8c8fed1, 2b3486bc2d237ec345b3942b7be5deabf8c8fed1unaffected
LinuxLinux6.3, 0, 6.6.76, 6.12.13, 6.13.2, 6.14affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.