Linux Kernel up to 6.4.3 netfilter nf_conntrack_dccp_packet stack-based overflow

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7.4	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.4.3 and classified as critical. Impacted is the function nf_conntrack_dccp_packet of the component netfilter. Executing a manipulation can lead to stack-based overflow. This vulnerability appears as CVE-2023-53333. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.4.3. It has been declared as critical. This vulnerability affects the function nf_conntrack_dccp_packet of the component netfilter. The manipulation with an unknown input leads to a stack-based overflow vulnerability. The CWE definition for the vulnerability is CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: dccp: copy entire header to stack buffer, not just basic one Eric Dumazet says: nf_conntrack_dccp_packet() has an unique: dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh); And nothing more is 'pulled' from the packet, depending on the content. dh->dccph_doff, and/or dh->dccph_x ...) So dccp_ack_seq() is happily reading stuff past the _dh buffer. BUG: KASAN: stack-out-of-bounds in nf_conntrack_dccp_packet+0x1134/0x11c0 Read of size 4 at addr ffff000128f66e0c by task syz-executor.2/29371 [..] Fix this by increasing the stack buffer to also include room for the extra sequence numbers and all the known dccp packet type headers, then pull again after the initial validation of the basic header. While at it, mark packets invalid that lack 48bit sequence bit but where RFC says the type MUST use them. Compile tested only. v2: first skb_header_pointer() now needs to adjust the size to only pull the generic header. (Eric) Heads-up: I intend to remove dccp conntrack support later this year.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2023-53333 since 09/16/2025. The exploitation appears to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 06/07/2026).

The vulnerability scanner Nessus provides a plugin with the ID 319448 (EulerOS Virtualization 2.13.1 : kernel (EulerOS-SA-2026-2132)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.251, 5.10.188, 5.15.121, 6.1.39, 6.3.13 or 6.4.4 eliminates this vulnerability. Applying the patch 337fdce450637ea663bc816edc2ba81e5cdad02e/9bdcda7abaf22f6453e5b5efb7eb4e524095d5d8/c052797ac36813419ad3bfa54cb8615db4b41f15/5c618daa5038712c4a4ef8923905a2ea1b8836a1/26bd1f210d3783a691052c51d76bb8a8bbd24c67/8c0980493beed3a80d6329c44ab293dc8c032927/ff0a3a7d52ff7282dbd183e7fc29a1fe386b0c30 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 (319448) and CERT Bund (WID-SEC-2025-2077). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IBM QRadar SIEM
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.250
• 5.10.187
• 5.15.120
• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.1.24
• 6.1.25
• 6.1.26
• 6.1.27
• 6.1.28
• 6.1.29
• 6.1.30
• 6.1.31
• 6.1.32
• 6.1.33
• 6.1.34
• 6.1.35
• 6.1.36
• 6.1.37
• 6.1.38
• 6.3.0
• 6.3.1
• 6.3.2
• 6.3.3
• 6.3.4
• 6.3.5
• 6.3.6
• 6.3.7
• 6.3.8
• 6.3.9
• 6.3.10
• 6.3.11
• 6.3.12
• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3

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: 7.6
VulDB Meta Temp Score: 7.4

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.1
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Stack-based overflow
CWE: CWE-121 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 319448
Nessus Name: EulerOS Virtualization 2.13.1 : kernel (EulerOS-SA-2026-2132)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.251/5.10.188/5.15.121/6.1.39/6.3.13/6.4.4
Patch: 337fdce450637ea663bc816edc2ba81e5cdad02e/9bdcda7abaf22f6453e5b5efb7eb4e524095d5d8/c052797ac36813419ad3bfa54cb8615db4b41f15/5c618daa5038712c4a4ef8923905a2ea1b8836a1/26bd1f210d3783a691052c51d76bb8a8bbd24c67/8c0980493beed3a80d6329c44ab293dc8c032927/ff0a3a7d52ff7282dbd183e7fc29a1fe386b0c30

Timelineinfo

09/16/2025 Advisory disclosed
09/16/2025 +0 days CVE reserved
09/16/2025 +0 days VulDB entry created
06/07/2026 +264 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2023-53333 (🔒)
GCVE (CVE): GCVE-0-2023-53333
GCVE (VulDB): GCVE-100-324538
CERT Bund: WID-SEC-2025-2077 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 09/16/2025 20:40
Updated: 06/07/2026 18:55
Changes: 09/16/2025 20:40 (59), 10/21/2025 06:25 (7), 12/10/2025 21:41 (11), 12/27/2025 13:13 (1), 06/07/2026 18:55 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion

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