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

CVE-2024-40957

Disclosure Date: July 12, 2024 •
CVE-2024-40957 CVSS v3 Base Score: 5.5
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

In the Linux kernel, the following vulnerability has been resolved:

seg6: fix parameter passing when calling NF_HOOK() in End.DX4 and End.DX6 behaviors

input_action_end_dx4() and input_action_end_dx6() are called NF_HOOK() for
PREROUTING hook, in PREROUTING hook, we should passing a valid indev,
and a NULL outdev to NF_HOOK(), otherwise may trigger a NULL pointer
dereference, as below:

[74830.647293] BUG: kernel NULL pointer dereference, address: 0000000000000090
[74830.655633] #PF: supervisor read access in kernel mode
[74830.657888] #PF: error_code(0x0000) - not-present page
[74830.659500] PGD 0 P4D 0
[74830.660450] Oops: 0000 [#1] PREEMPT SMP PTI
...
[74830.664953] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[74830.666569] RIP: 0010:rpfilter_mt+0x44/0x15e [ipt_rpfilter]
...
[74830.689725] Call Trace:
[74830.690402]  <IRQ>
[74830.690953]  ? show_trace_log_lvl+0x1c4/0x2df
[74830.692020]  ? show_trace_log_lvl+0x1c4/0x2df
[74830.693095]  ? ipt_do_table+0x286/0x710 [ip_tables]
[74830.694275]  ? __die_body.cold+0x8/0xd
[74830.695205]  ? page_fault_oops+0xac/0x140
[74830.696244]  ? exc_page_fault+0x62/0x150
[74830.697225]  ? asm_exc_page_fault+0x22/0x30
[74830.698344]  ? rpfilter_mt+0x44/0x15e [ipt_rpfilter]
[74830.699540]  ipt_do_table+0x286/0x710 [ip_tables]
[74830.700758]  ? ip6_route_input+0x19d/0x240
[74830.701752]  nf_hook_slow+0x3f/0xb0
[74830.702678]  input_action_end_dx4+0x19b/0x1e0
[74830.703735]  ? input_action_end_t+0xe0/0xe0
[74830.704734]  seg6_local_input_core+0x2d/0x60
[74830.705782]  lwtunnel_input+0x5b/0xb0
[74830.706690]  __netif_receive_skb_one_core+0x63/0xa0
[74830.707825]  process_backlog+0x99/0x140
[74830.709538]  __napi_poll+0x2c/0x160
[74830.710673]  net_rx_action+0x296/0x350
[74830.711860]  __do_softirq+0xcb/0x2ac
[74830.713049]  do_softirq+0x63/0x90

input_action_end_dx4() passing a NULL indev to NF_HOOK(), and finally
trigger a NULL dereference in rpfilter_mt()–>rpfilter_is_loopback():

static bool
rpfilter_is_loopback(const struct sk_buff *skb,
      	       const struct net_device *in)
{
        // in is NULL
        return skb->pkt_type == PACKET_LOOPBACK ||
      	 in->flags & IFF_LOOPBACK;
}

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CVSS V3 Severity and Metrics
Base Score:
5.5 Medium
Impact Score:
3.6
Exploitability Score:
1.8
Vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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):
None
Integrity (I):
None
Availability (A):
High

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Linux af90e3d73dc4
Linux not down converted
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • linux

Products

  • linux kernel,
  • linux kernel 6.10
Technical Analysis