Linux Kernel up to 6.4.9 net DCB_ATTR_BCN privilege escalation

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5.4$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 5.4.252/5.10.189/5.15.125/6.1.44/6.4.9. This affects the function DCB_ATTR_BCN of the component net. Performing a manipulation results in an unknown weakness. This vulnerability was named CVE-2023-53369. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.4.252/5.10.189/5.15.125/6.1.44/6.4.9. It has been classified as critical. This affects the function DCB_ATTR_BCN of the component net. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: dcb: choose correct policy to parse DCB_ATTR_BCN The dcbnl_bcn_setcfg uses erroneous policy to parse tb[DCB_ATTR_BCN], which is introduced in commit 859ee3c43812 ("DCB: Add support for DCB BCN"). Please see the comment in below code static int dcbnl_bcn_setcfg(...) { ... ret = nla_parse_nested_deprecated(..., dcbnl_pfc_up_nest, .. ) // !!! dcbnl_pfc_up_nest for attributes // DCB_PFC_UP_ATTR_0 to DCB_PFC_UP_ATTR_ALL in enum dcbnl_pfc_up_attrs ... for (i = DCB_BCN_ATTR_RP_0; i <= DCB_BCN_ATTR_RP_7; i++) { // !!! DCB_BCN_ATTR_RP_0 to DCB_BCN_ATTR_RP_7 in enum dcbnl_bcn_attrs ... value_byte = nla_get_u8(data[i]); ... } ... for (i = DCB_BCN_ATTR_BCNA_0; i <= DCB_BCN_ATTR_RI; i++) { // !!! DCB_BCN_ATTR_BCNA_0 to DCB_BCN_ATTR_RI in enum dcbnl_bcn_attrs ... value_int = nla_get_u32(data[i]); ... } ... } That is, the nla_parse_nested_deprecated uses dcbnl_pfc_up_nest attributes to parse nlattr defined in dcbnl_pfc_up_attrs. But the following access code fetch each nlattr as dcbnl_bcn_attrs attributes. By looking up the associated nla_policy for dcbnl_bcn_attrs. We can find the beginning part of these two policies are "same". static const struct nla_policy dcbnl_pfc_up_nest[...] = { [DCB_PFC_UP_ATTR_0] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_1] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_2] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_3] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_4] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_5] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_6] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_7] = {.type = NLA_U8}, [DCB_PFC_UP_ATTR_ALL] = {.type = NLA_FLAG}, }; static const struct nla_policy dcbnl_bcn_nest[...] = { [DCB_BCN_ATTR_RP_0] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_1] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_2] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_3] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_4] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_5] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_6] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_7] = {.type = NLA_U8}, [DCB_BCN_ATTR_RP_ALL] = {.type = NLA_FLAG}, // from here is somewhat different [DCB_BCN_ATTR_BCNA_0] = {.type = NLA_U32}, ... [DCB_BCN_ATTR_ALL] = {.type = NLA_FLAG}, }; Therefore, the current code is buggy and this nla_parse_nested_deprecated could overflow the dcbnl_pfc_up_nest and use the adjacent nla_policy to parse attributes from DCB_BCN_ATTR_BCNA_0. Hence use the correct policy dcbnl_bcn_nest to parse the nested tb[DCB_ATTR_BCN] TLV.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2023-53369 since 09/17/2025. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 265583 (Linux Distros Unpatched Vulnerability : CVE-2023-53369), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.253, 5.10.190, 5.15.126, 6.1.45 or 6.4.10 eliminates this vulnerability. Applying the patch 5b3dbedb8d4a0f9f7ce904d76b885438af2a21f9/8e309f43d0ca4051d20736c06a6f84bbddd881da/a0da2684db18dead3bcee12fb185e596e3d63c2b/ecff20e193207b44fdbfe64d7de89890f0a7fe6c/199fde04bd875d28b3a5ca525eaaa004eec6e947/31d49ba033095f6e8158c60f69714a500922e0c3 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 (265583) and CERT Bund (WID-SEC-2025-2092). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

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

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 265583
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2023-53369

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.253/5.10.190/5.15.126/6.1.45/6.4.10
Patch: 5b3dbedb8d4a0f9f7ce904d76b885438af2a21f9/8e309f43d0ca4051d20736c06a6f84bbddd881da/a0da2684db18dead3bcee12fb185e596e3d63c2b/ecff20e193207b44fdbfe64d7de89890f0a7fe6c/199fde04bd875d28b3a5ca525eaaa004eec6e947/31d49ba033095f6e8158c60f69714a500922e0c3

Timelineinfo

09/17/2025 CVE reserved
09/18/2025 +1 days Advisory disclosed
09/18/2025 +0 days VulDB entry created
12/13/2025 +86 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2023-53369 (🔒)
GCVE (CVE): GCVE-0-2023-53369
GCVE (VulDB): GCVE-100-324843
CERT Bund: WID-SEC-2025-2092 - Linux Kernel: Mehrere Schwachstellen erm&ouml;glichen Denial of Service

Entryinfo

Created: 09/18/2025 16:21
Updated: 12/13/2025 02:33
Changes: 09/18/2025 16:21 (58), 09/20/2025 03:37 (7), 09/20/2025 20:46 (2), 11/29/2025 15:09 (1), 12/13/2025 02:33 (10)
Complete: 🔍
Cache ID: 216::103

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