boxscore/security
CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-47309HIGH
Linux Linux — net: validate lwtstate->data before returning from skb_tunnel_info()
  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  H  N  H    7.1   .0025   16.4     —
AFFECTED
  Product  Versions                                    Fixed
  Linux    61adedf3e3f1d3f032c5a6a299978d91eff6d555 –  —
  Linux    4.3 –                                       4.4.277
TIMELINE
  May 21  Reserved by Linux
  May 21  Published (CNA: Linux)
  Aug 4   RESCORED — CVE-2021-47309 (Linux). CVSS 7.8 → 7.1 (NVD).
CWE-125 · CNA: Linux · CVSS v3.1 · 8 references · NVD status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: net: validate lwtstate->data before returning from skb_tunnel_info() skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info type without validation. lwtstate->data can have various types such as mpls_iptunnel_encap, etc and these are not compatible. So skb_tunnel_info() should validate before returning that pointer. Splat looks like: BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan] Read of size 2 at addr ffff888106ec2698 by task ping/811 CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195 Call Trace: dump_stack_lvl+0x56/0x7b print_address_description.constprop.8.cold.13+0x13/0x2ee ? vxlan_get_route+0x418/0x4b0 [vxlan] ? vxlan_get_route+0x418/0x4b0 [vxlan] kasan_report.cold.14+0x83/0xdf ? vxlan_get_route+0x418/0x4b0 [vxlan] vxlan_get_route+0x418/0x4b0 [vxlan] [ ... ] vxlan_xmit_one+0x148b/0x32b0 [vxlan] [ ... ] vxlan_xmit+0x25c5/0x4780 [vxlan] [ ... ] dev_hard_start_xmit+0x1ae/0x6e0 __dev_queue_xmit+0x1f39/0x31a0 [ ... ] neigh_xmit+0x2f9/0x940 mpls_xmit+0x911/0x1600 [mpls_iptunnel] lwtunnel_xmit+0x18f/0x450 ip_finish_output2+0x867/0x2040 [ ... ]

Lifecycle

Complete event history — 3 events, chronological
DateEventDetail
May 21, 2024ReservedReserved by Linux
May 21, 2024PublishedPublished (CNA: Linux)
August 4, 2026RESCOREDRESCORED — CVE-2021-47309 (Linux). CVSS 7.8 → 7.1 (NVD).

Affected

Affected products and packages — 2 rows
VendorProduct / PackageEcosystemVersion introducedFixed
LinuxLinux—61adedf3e3f1d3f032c5a6a299978d91eff6d555—
LinuxLinux—4.34.4.277

Weaknesses

CWE-125

References (8)

Related

Authoritative record: CVE-2021-47309 at cve.org

Vendors: linux

Weaknesses: CWE-125

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-47309 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.