CVE-2023-53333

High

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.

Package Linux Kernel
Published 2025-09-16
Last modified 2026-01-14
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.1

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness type

CWE-125

CVE-2023-53333 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 2.6.26 and later are affected. Fixed in 5.4.251, 5.10.188, 5.15.121, 6.1.39, 6.3.13, 6.4.4, 6.5 and their respective stable series.

Affected from
≥ 2.6.26
Fixed in
✓ 5.4.251 5.4.x ✓ 5.10.188 5.10.x ✓ 5.15.121 5.15.x ✓ 6.1.39 6.1.x ✓ 6.3.13 6.3.x ✓ 6.4.4 6.4.x ✓ 6.5

References

The following references provide additional information about CVE-2023-53333 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

7 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2023-53333?

    CVE-2023-53333 is a High severity Linux kernel vulnerability with a CVSS score of 7.1 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 2.6.26 onward and has been patched in 5.4.251, 5.10.188, 5.15.121 and others. CVE-2023-53333 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2023-53333?

    CVE-2023-53333 has a CVSS score of 7.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H .

  • Is there a patch available for CVE-2023-53333?

    Yes — CVE-2023-53333 has been patched. Fixed versions include 5.4.251, 5.10.188, 5.15.121 and others. If you are running Linux kernel 2.6.26 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2023-53333 actively exploited?

    No — CVE-2023-53333 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Out-of-bounds Read (CWE-125)?

    The product reads data past the end or before the beginning of the intended buffer. View CWE-125 on MITRE CWE →

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