CVE-2026-7422: CWE-290: Authentication Bypass by Spoofing in AWS FreeRTOS-Plus-TCP
Insufficient packet validation in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to bypass all checksum and minimum-size validation by spoofing the Ethernet source MAC address to match one of the device's own registered endpoints, because the loopback detection mechanism skips all input validation for packets whose source MAC matches a local endpoint. To mitigate this issue, users should upgrade to the fixed version when available.
AI Analysis
Technical Summary
AWS FreeRTOS-Plus-TCP before versions 4.2.6 and 4.4.1 contains a vulnerability (CVE-2026-7422) due to insufficient packet validation. Specifically, the loopback detection mechanism skips validation for packets whose Ethernet source MAC address matches a local endpoint, enabling an adjacent attacker to spoof such packets and bypass checksum and minimum-size checks. This results in an authentication bypass by spoofing (CWE-290). The vulnerability affects versions 4.0.0 through 4.3.0. AWS provides a patch to address this issue and manages remediation for this cloud-hosted service.
Potential Impact
An adjacent network attacker can bypass all checksum and minimum-size validation by spoofing the Ethernet source MAC address to match a device's registered endpoint. This allows the attacker to bypass authentication mechanisms relying on these validations, potentially leading to unauthorized actions or data manipulation within the affected FreeRTOS-Plus-TCP environment. There is no reported impact on confidentiality or availability, and no known exploits are currently in the wild.
Mitigation Recommendations
A patch is available to fix this vulnerability. Users should upgrade FreeRTOS-Plus-TCP to version 4.2.6 or later, or 4.4.1 or later, as recommended by AWS. Since this is a cloud-hosted service, AWS manages remediation on their side. Users should consult the AWS security bulletin at https://aws.amazon.com/security/security-bulletins/2026-021-aws/ for the latest guidance and ensure their deployments are updated accordingly.
CVE-2026-7422: CWE-290: Authentication Bypass by Spoofing in AWS FreeRTOS-Plus-TCP
Description
Insufficient packet validation in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to bypass all checksum and minimum-size validation by spoofing the Ethernet source MAC address to match one of the device's own registered endpoints, because the loopback detection mechanism skips all input validation for packets whose source MAC matches a local endpoint. To mitigate this issue, users should upgrade to the fixed version when available.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
AWS FreeRTOS-Plus-TCP before versions 4.2.6 and 4.4.1 contains a vulnerability (CVE-2026-7422) due to insufficient packet validation. Specifically, the loopback detection mechanism skips validation for packets whose Ethernet source MAC address matches a local endpoint, enabling an adjacent attacker to spoof such packets and bypass checksum and minimum-size checks. This results in an authentication bypass by spoofing (CWE-290). The vulnerability affects versions 4.0.0 through 4.3.0. AWS provides a patch to address this issue and manages remediation for this cloud-hosted service.
Potential Impact
An adjacent network attacker can bypass all checksum and minimum-size validation by spoofing the Ethernet source MAC address to match a device's registered endpoint. This allows the attacker to bypass authentication mechanisms relying on these validations, potentially leading to unauthorized actions or data manipulation within the affected FreeRTOS-Plus-TCP environment. There is no reported impact on confidentiality or availability, and no known exploits are currently in the wild.
Mitigation Recommendations
A patch is available to fix this vulnerability. Users should upgrade FreeRTOS-Plus-TCP to version 4.2.6 or later, or 4.4.1 or later, as recommended by AWS. Since this is a cloud-hosted service, AWS manages remediation on their side. Users should consult the AWS security bulletin at https://aws.amazon.com/security/security-bulletins/2026-021-aws/ for the latest guidance and ensure their deployments are updated accordingly.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- AMZN
- Date Reserved
- 2026-04-29T14:27:48.592Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Is Cloud Service
- true
- Vendor Advisory Urls
- [{"url":"https://aws.amazon.com/security/security-bulletins/2026-021-aws/","vendor":"AWS"}]
Threat ID: 69f256b0cbff5d86103eb484
Added to database: 4/29/2026, 7:06:24 PM
Last enriched: 4/29/2026, 7:21:48 PM
Last updated: 4/29/2026, 8:09:54 PM
Views: 4
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