CVE-2025-39812

  • Published: 2025-09-16T13:15:54.537

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

sctp: initialize more fields in sctp_v6_from_sk()

syzbot found that sin6_scope_id was not properly initialized,
leading to undefined behavior.

Clear sin6_scope_id and sin6_flowinfo.

BUG: KMSAN: uninit-value in __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649
__sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649
sctp_inet6_cmp_addr+0x4f2/0x510 net/sctp/ipv6.c:983
sctp_bind_addr_conflict+0x22a/0x3b0 net/sctp/bind_addr.c:390
sctp_get_port_local+0x21eb/0x2440 net/sctp/socket.c:8452
sctp_get_port net/sctp/socket.c:8523 [inline]
sctp_listen_start net/sctp/socket.c:8567 [inline]
sctp_inet_listen+0x710/0xfd0 net/sctp/socket.c:8636
__sys_listen_socket net/socket.c:1912 [inline]
__sys_listen net/socket.c:1927 [inline]
__do_sys_listen net/socket.c:1932 [inline]
__se_sys_listen net/socket.c:1930 [inline]
__x64_sys_listen+0x343/0x4c0 net/socket.c:1930
x64_sys_call+0x271d/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:51
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable addr.i.i created at:
sctp_get_port net/sctp/socket.c:8515 [inline]
sctp_listen_start net/sctp/socket.c:8567 [inline]
sctp_inet_listen+0x650/0xfd0 net/sctp/socket.c:8636
__sys_listen_socket net/socket.c:1912 [inline]
__sys_listen net/socket.c:1927 [inline]
__do_sys_listen net/socket.c:1932 [inline]
__se_sys_listen net/socket.c:1930 [inline]
__x64_sys_listen+0x343/0x4c0 net/socket.c:1930

Related CVE by CWE

No related CWE found.

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Recently Exploited Similar Vulnerabilities

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How to fix CVE-2025-39812

CVE-2025-39812 is a unknown severity vulnerability affecting the affected product.

Description: In the Linux kernel, the following vulnerability has been resolved: sctp: initialize more fields in sctp_v6_from_sk() syzbot found that sin6_scope_id was not properly initialized, leading to undefined behavior. Clear sin6_scope_id and sin6_flowinfo. BUG: KMSAN: uninit-value in __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649 __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649 sctp_inet6_cmp_addr+0x4f2/0x510 net/sctp/ipv6.c:983 sctp_bind_addr_conflict+0x22a/0x3b0 net/sctp/bind_addr.c:390 sctp_get_port_local+0x21eb/0x2440 net/sctp/socket.c:8452 sctp_get_port net/sctp/socket.c:8523 [inline] sctp_listen_start net/sctp/socket.c:8567 [inline] sctp_inet_listen+0x710/0xfd0 net/sctp/socket.c:8636 __sys_listen_socket […]

Exploit Difficulty: HARD
⏱️ Time to exploit: > 4 hours
🛠️ Required skills: Advanced security expertise
💰 Public exploits: Rare or not public

How to Fix:

1 Identify affected systems

- Check if you're running the affected product

2 Immediate actions

- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access

3 Verification

- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)

4 Long-term prevention

- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations

Exploit Difficulty Assessment

HARD
⏱️ Time to Exploit: > 4 hours
🛠️ Skills Required: Advanced security expertise
💰 Public Exploits: Rare or not public

Vulnerability Timeline

Sep 16, 2025
Vulnerability Published

CVE details first published to NVD database

Nov 12, 2025
Imported to Database

Added to this CVE tracking system

Detection Rules & IOCs

No specific detection rules generated for this vulnerability type.

No vendor/product data available.