CVE-2025-66442

import time import statistics # Conceptual PoC for Timing Side Channel Analysis # This script demonstrates how to measure potential timing variations. # Requires a local environment with the vulnerable library. def vulnerable_decrypt(ciphertext): # Placeholder for the actual vulnerable decryption function # In a real scenario, this calls the Mbed TLS API pass def measure_timing(func, data, iterations=1000): timings = [] for _ in range(iterations): start = time.perf_counter_ns() func(data) end = time.perf_counter_ns() timings.append(end - start) return timings # Attack Simulation # attacker_controlled_ciphertext = "..." # results = measure_timing(vulnerable_decrypt, attacker_controlled_ciphertext) # print(f"Average time: {statistics.mean(results)} ns") # analyze_variance(results)

{"cve": {"id": "CVE-2025-66442", "sourceIdentifier": "[email protected]", "published": "2026-04-01T20:16:22.107", "lastModified": "2026-04-03T20:04:38.487", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In Mbed TLS through 4.0.0, there is a compiler-induced timing side channel (in RSA and CBC/ECB decryption) that only occurs with LLVM's select-optimize feature. TF-PSA-Crypto through 1.0.0 is also affected."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 5.1, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.4, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-385"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:arm:mbed_tls:*:*:*:*:*:*:*:*", "versionEndIncluding": "4.0.0", "matchCriteriaId": "E63DA70A-502D-4389-B0BE-51F0227F1151"}, {"vulnerable": true, "criteria": "cpe:2.3:a:arm:tf-psa-crypto:*:*:*:*:*:*:*:*", "versionEndIncluding": "1.0.0", "matchCriteriaId": "0A5B330B-0928-4C3E-9CC2-B2E4D81D96DE"}]}]}], "references": [{"url": "https://github.com/Mbed-TLS/TF-PSA-Crypto/releases", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/Mbed-TLS/mbedtls/releases", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://mbed-tls.readthedocs.io/en/latest/security-advisories/", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-compiler-induced-constant-time-violations/", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}