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Invalid Pointer Dereference when receiving UDP/IPv6 packets

Moderate
KeishiSonoda published GHSA-6fh9-mqxj-hmwj Oct 10, 2025

Package

FreeRTOS-Plus-TCP

Affected versions

See Advisory

Patched versions

4.3.4

Description

Summary

FreeRTOS-Plus-TCP is an open source TCP/IP stack implementation specifically designed for FreeRTOS. The stack provides a standard Berkeley sockets interface and supports essential networking protocols including IPv6, ARP, DHCP, DNS, LLMNR, mDNS, NBNS, RA, ND, ICMP, and ICMPv6. An issue exists where, under certain circumstances, FreeRTOS-Plus-TCP may allow Invalid Pointer Dereference.

Impact

An invalid pointer dereference when processing a UDP/IPv6 packet with an incorrect IP version field in the packet header.

This issue only affects applications using IPv6.

Impacted versions: v4.0.0 to v4.3.3, if IPv6 support is enabled.

Patches

This issue has been addressed in FreeRTOS-Plus-TCP version 4.3.4. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.

Workarounds

None.

References

If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.

Acknowledgement

We would like to thank Ivan Gotovchits of Mayhem Security for collaborating on this issue through the coordinated vulnerability disclosure process.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

CVE ID

CVE-2025-11618

Weaknesses

NULL Pointer Dereference

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Learn more on MITRE.