IM
IronMonkey Threat Research

CVE-2025-38732 MEDIUM

Published: 2025-09-05 | Last Modified: 2026-07-14 | Status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_reject: don't leak dst refcount for loopback packets recent patches to add a WARN() when replacing skb dst entry found an old bug: WARNING: include/linux/skbuff.h:1165 skb_dst_check_unset include/linux/skbuff.h:1164 [inline] WARNING: include/linux/skbuff.h:1165 skb_dst_set include/linux/skbuff.h:1210 [inline] WARNING: include/linux/skbuff.h:1165 nf_reject_fill_skb_dst+0x2a4/0x330 net/ipv4/netfilter/nf_reject_ipv4.c:234 [..] Call Trace: nf_send_unreach+0x17b/0x6e0 net/ipv4/netfilter/nf_reject_ipv4.c:325 nft_reject_inet_eval+0x4bc/0x690 net/netfilter/nft_reject_inet.c:27 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] .. This is because blamed commit forgot about loopback packets. Such packets already have a dst_entry attached, even at PRE_ROUTING stage. Instead of checking hook just check if the skb already has a route attached to it.

CVSS Metrics

Base Score: 5.5 (MEDIUM)

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

Attack VectorLOCAL
Attack ComplexityLOW
Privileges RequiredLOW
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactNONE
Integrity ImpactNONE
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 1.8

Impact Score: 3.6

Weaknesses

Source Type Description
[email protected] Primary
en NVD-CWE-Other

Affected Products

Vendor Product Version Update Type
linux linux_kernel * <built-in method update of dict object at 0x7d23beb87500> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d2424650d00> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d23be9fd480> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d236440de00> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d2364416300> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d23a52f6800> Operating System
linux linux_kernel 6.17 <built-in method update of dict object at 0x7d2424653600> Operating System
linux linux_kernel 6.17 <built-in method update of dict object at 0x7d236440da80> Operating System
debian debian_linux 11.0 <built-in method update of dict object at 0x7d2424652340> Operating System

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References

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