VDB-297737 · CVE-2025-21705 · Nessus 232678

Linux Kernel up to 6.1.128/6.6.75/6.12.12/6.13.1 mptcp net/mptcp/protocol.c information disclosure

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4.0	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 6.1.128/6.6.75/6.12.12/6.13.1. Affected by this vulnerability is an unknown functionality of the file net/mptcp/protocol.c of the component mptcp. The manipulation leads to information disclosure. This vulnerability is uniquely identified as CVE-2025-21705. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.128/6.6.75/6.12.12/6.13.1. It has been rated as problematic. This issue affects some unknown processing of the file net/mptcp/protocol.c of the component mptcp. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: mptcp: handle fastopen disconnect correctly Syzbot was able to trigger a data stream corruption: WARNING: CPU: 0 PID: 9846 at net/mptcp/protocol.c:1024 __mptcp_clean_una+0xddb/0xff0 net/mptcp/protocol.c:1024 Modules linked in: CPU: 0 UID: 0 PID: 9846 Comm: syz-executor351 Not tainted 6.13.0-rc2-syzkaller-00059-g00a5acdbf398 #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 RIP: 0010:__mptcp_clean_una+0xddb/0xff0 net/mptcp/protocol.c:1024 Code: fa ff ff 48 8b 4c 24 18 80 e1 07 fe c1 38 c1 0f 8c 8e fa ff ff 48 8b 7c 24 18 e8 e0 db 54 f6 e9 7f fa ff ff e8 e6 80 ee f5 90 0b 90 4c 8b 6c 24 40 4d 89 f4 e9 04 f5 ff ff 44 89 f1 80 e1 07 RSP: 0018:ffffc9000c0cf400 EFLAGS: 00010293 RAX: ffffffff8bb0dd5a RBX: ffff888033f5d230 RCX: ffff888059ce8000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000c0cf518 R08: ffffffff8bb0d1dd R09: 1ffff110170c8928 R10: dffffc0000000000 R11: ffffed10170c8929 R12: 0000000000000000 R13: ffff888033f5d220 R14: dffffc0000000000 R15: ffff8880592b8000 FS: 00007f6e866496c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6e86f491a0 CR3: 00000000310e6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mptcp_clean_una_wakeup+0x7f/0x2d0 net/mptcp/protocol.c:1074 mptcp_release_cb+0x7cb/0xb30 net/mptcp/protocol.c:3493 release_sock+0x1aa/0x1f0 net/core/sock.c:3640 inet_wait_for_connect net/ipv4/af_inet.c:609 [inline] __inet_stream_connect+0x8bd/0xf30 net/ipv4/af_inet.c:703 mptcp_sendmsg_fastopen+0x2a2/0x530 net/mptcp/protocol.c:1755 mptcp_sendmsg+0x1884/0x1b10 net/mptcp/protocol.c:1830 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6e86ebfe69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 1f 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6e86649168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f6e86f491b8 RCX: 00007f6e86ebfe69 RDX: 0000000030004001 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00007f6e86f491b0 R08: 00007f6e866496c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6e86f491bc R13: 000000000000006e R14: 00007ffe445d9420 R15: 00007ffe445d9508 The root cause is the bad handling of disconnect() generated internally by the MPTCP protocol in case of connect FASTOPEN errors. Address the issue increasing the socket disconnect counter even on such a case, to allow other threads waiting on the same socket lock to properly error out.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2025-21705 since 12/29/2024. The exploitation is known to be difficult. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 232678 (SUSE SLES15 / openSUSE 15 Security Update : kernel (SUSE-SU-2025:0847-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.129, 6.6.76, 6.12.13, 6.13.2 or 6.14-rc1 eliminates this vulnerability. Applying the patch 73e268b4be27b36ae68ea10755cb003f43b38884/84ac44d9fed3a56440971cbd7600a02b70b5b32a/6ec806762318a4adde0ea63342d42d0feae95079/619af16b3b57a3a4ee50b9a30add9ff155541e71 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (232678) and CERT Bund (WID-SEC-2025-0453). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

Google Container-Optimized OS
Debian Linux
Amazon Linux 2
Red Hat Enterprise Linux
Ubuntu Linux
SUSE Linux
Oracle Linux
Siemens SIMATIC S7
RESF Rocky Linux
Dell NetWorker
Dell Avamar
Red Hat OpenShift
IBM QRadar SIEM
SolarWinds Security Event Manager
Dell PowerProtect Data Domain
Open Source Linux Kernel
IBM DataPower Gateway
Dell Secure Connect Gateway
Dell PowerScale OneFS
Dell ECS

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.0
VulDB Meta Temp Score: 4.0

VulDB Base Score: 2.6
VulDB Temp Score: 2.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍