Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
0

CVE-2021-47309

Disclosure Date: May 21, 2024 •
CVE-2021-47309 CVSS v3 Base Score: 7.1
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

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 Severity and Metrics
Base Score:
7.1 High
Impact Score:
5.2
Exploitability Score:
1.8
Vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
None
Availability (A):
High

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Linux e7f3c9df4051
Linux not down converted
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown
Technical Analysis