CVE-2021-47309

HIGH
Published May 21, 2024 Modified Dec 26, 2024 CWE-125

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 [ ... ]

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CVSS v3.1 Score

7.1
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/2179d96ec702cc33ead02a9ce40ece599b8538c5 https://git.kernel.org/stable/c/67a9c94317402b826fc3db32afc8f39336803d97 https://git.kernel.org/stable/c/83bdcfbd968bcc91a0632b7b625e4a9b0cba5e0d https://git.kernel.org/stable/c/8aa13a86964cdec4fd969ef677c6614ff068641a https://git.kernel.org/stable/c/8bb1589c89e61e3b182dd546f1021928ebb5c2a6 https://git.kernel.org/stable/c/a915379594f1e045421635c6316d8f3ffa018c58 https://git.kernel.org/stable/c/b61d327cd3cc5ea591f3bf751dd11e034f388bb5 https://git.kernel.org/stable/c/e7f3c9df40515a6c6b46f36c4c94cf48a043f887 https://git.kernel.org/stable/c/2179d96ec702cc33ead02a9ce40ece599b8538c5 https://git.kernel.org/stable/c/67a9c94317402b826fc3db32afc8f39336803d97 https://git.kernel.org/stable/c/83bdcfbd968bcc91a0632b7b625e4a9b0cba5e0d https://git.kernel.org/stable/c/8aa13a86964cdec4fd969ef677c6614ff068641a https://git.kernel.org/stable/c/8bb1589c89e61e3b182dd546f1021928ebb5c2a6 https://git.kernel.org/stable/c/a915379594f1e045421635c6316d8f3ffa018c58 https://git.kernel.org/stable/c/b61d327cd3cc5ea591f3bf751dd11e034f388bb5 https://git.kernel.org/stable/c/e7f3c9df40515a6c6b46f36c4c94cf48a043f887

Frequently Asked Questions

What is CVE-2021-47309? +
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 [ ... ] It has a CVSS v3.1 base score of 7.1 (HIGH).
How severe is CVE-2021-47309? +
CVE-2021-47309 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2021-47309? +
CVE-2021-47309 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2021-47309? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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