CVE-2023-46838

Linux: netback processing of zero-length transmit fragment

HIGH
7.5
CVSS Score
Published: January 29, 2024 at 10:18 AM UTC
Updated: June 17, 2026 at 06:31 AM UTC
3 products affected across 3 vendorsLinux KernelDebian LinuxFedora

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Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

Transmit requests in Xen's virtual network protocol can consist of multiple parts. While not really useful, except for the initial part any of them may be of zero length, i.e. carry no data at all. Besides a certain initial portion of the to be transferred data, these parts are directly translated into what Linux calls SKB fragments. Such converted request parts can, when for a particular SKB they are all of length zero, lead to a de-reference of NULL in core networking code.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.14 ≤ v < 4.19.3064.20 ≤ v < 5.4.2685.11 ≤ v < 5.15.1485.16 ≤ v < 6.1.755.5 ≤ v < 5.10.2096.2 ≤ v < 6.6.146.7 ≤ v < 6.7.2
Affected range stops below 4.19.306, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.10.209, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.15.148, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.4.268, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.1.75, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.6.14, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.7.2, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in consult Xen advisory XSA-448 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-476

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