CVE-2026-34155

import os # This is a conceptual PoC demonstrating the creation of a large file # that could trigger the integer overflow condition in vulnerable RAUC versions. # Actual exploitation requires a valid private key to sign the bundle header. def create_malicious_bundle(filename, size_gb=3): """ Creates a dummy file > 2GB to simulate the overflow condition. """ file_size = size_gb * 1024 * 1024 * 1024 # In a real scenario, the first few bytes would contain a valid signed header # and the rest would be the malicious payload. with open(filename, 'wb') as f: # Write a dummy header (e.g., 1KB) f.write(b'A' * 1024) # Write padding to exceed 2GB limit (triggering overflow) # This represents the unsigned portion where malicious code resides remaining = file_size - 1024 f.write(b'B' * remaining) print(f"Created {filename} with size {size_gb}GB.") print("If signed with a valid key, RAUC < 1.15.2 may only verify the first 1KB.") if __name__ == "__main__": create_malicious_bundle("malicious_bundle.rauc")

{"cve": {"id": "CVE-2026-34155", "sourceIdentifier": "[email protected]", "published": "2026-03-31T14:16:11.997", "lastModified": "2026-04-03T15:53:01.463", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "RAUC controls the update process on embedded Linux systems. Prior to version 1.15.2, RAUC bundles using the 'plain' format exceeding a payload size of 2 GiB cause an integer overflow which results in a signature which covers only the first few bytes of the payload. Given such a bundle with a legitimate signature, an attacker can modify the part of the payload which is not covered by the signature. This issue has been patched in version 1.15.2."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:L/VI:H/VA:N/SC:H/SI:H/SA:H/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": 7.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "subAvailabilityImpact": "HIGH", "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": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-196"}, {"lang": "en", "value": "CWE-347"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:pengutronix:rauc:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.15.2", "matchCriteriaId": "E4EC7982-C7EC-4B8C-9098-A1B567B10FAF"}]}]}], "references": [{"url": "https://github.com/rauc/rauc/commit/4fb7c798d6ae412344fb8f8d310d773046af3441", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/rauc/rauc/releases/tag/v1.15.2", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/rauc/rauc/security/advisories/GHSA-6hj7-q844-m2hx", "source": "[email protected]", "tags": ["Mitigation", "Patch", "Vendor Advisory"]}]}}