179 lines
8.2 KiB
JSON
179 lines
8.2 KiB
JSON
{
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"dataType": "CVE_RECORD",
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"dataVersion": "5.2",
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"cveMetadata": {
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"cveId": "CVE-2026-63569",
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"assignerOrgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
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"state": "PUBLISHED",
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"assignerShortName": "bcorg",
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"dateReserved": "2026-07-16T23:48:46.076Z",
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"datePublished": "2026-10-02T07:00:23.526Z",
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"dateUpdated": "2026-10-02T19:07:59.005Z"
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},
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"containers": {
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"cna": {
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"providerMetadata": {
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"orgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
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"shortName": "bcorg",
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"dateUpdated": "2026-10-02T07:00:23.526Z"
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},
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"title": "MTI/A0 DHAgreement does not validate the peer's ephemeral value",
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"problemTypes": [
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{
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"descriptions": [
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{
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"lang": "en",
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"cweId": "CWE-20",
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"description": "CWE-20 Improper Input Validation",
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"type": "CWE"
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}
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]
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}
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],
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"impacts": [
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{
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"descriptions": [
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{
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"lang": "en",
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"value": "Loss of confidentiality and integrity (attacker-known shared secret; leakage or recovery of the static DH private key)"
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}
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]
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}
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],
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"affected": [
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{
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"vendor": "Legion of the Bouncy Castle Inc.",
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"product": "bc-csharp",
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"collectionURL": "https://www.nuget.org/packages/BouncyCastle.Cryptography",
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"packageName": "BouncyCastle.Cryptography",
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"repo": "https://github.com/bcgit/bc-csharp",
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"programFiles": [
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"crypto/src/crypto/agreement/DHAgreement.cs"
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],
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"versions": [
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{
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"status": "affected",
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"version": "0",
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"lessThan": "2.7.0",
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"versionType": "semver"
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}
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],
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"defaultStatus": "unaffected"
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}
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],
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"descriptions": [
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{
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"lang": "en",
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"value": "Improper input validation in DHAgreement.CalculateAgreement (MTI/A0 two-pass Diffie-Hellman) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an on-path attacker to make the local party compute an agreed value the attacker already knows, defeating the key authentication MTI/A0 is meant to provide. It also allows a malicious peer to learn the local static private key modulo the small factors of p-1, and to recover it entirely in groups with many such factors. The attack uses a crafted out-of-range or small-order ephemeral value, and works because that value is raised to the static private key without the range and subgroup-membership checks applied to DH public keys. Only applications that call DHAgreement directly are affected.",
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"supportingMedia": [
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{
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"type": "text/html",
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"base64": false,
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"value": "Improper input validation in DHAgreement.CalculateAgreement (MTI/A0 two-pass Diffie-Hellman) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an on-path attacker to make the local party compute an agreed value the attacker already knows, defeating the key authentication MTI/A0 is meant to provide. It also allows a malicious peer to learn the local static private key modulo the small factors of p-1, and to recover it entirely in groups with many such factors. The attack uses a crafted out-of-range or small-order ephemeral value, and works because that value is raised to the static private key without the range and subgroup-membership checks applied to DH public keys. Only applications that call DHAgreement directly are affected."
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}
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]
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}
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],
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"references": [
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{
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"url": "https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63569",
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"tags": [
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"vendor-advisory"
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]
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},
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{
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"url": "https://github.com/bcgit/bc-csharp/commit/fe236ad207c5960eeae1ebb6560c783a3bb5b692",
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"tags": [
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"patch"
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]
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}
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],
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"metrics": [
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{
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"format": "CVSS",
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"scenarios": [
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{
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"lang": "en",
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"value": "GENERAL"
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}
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],
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"cvssV4_0": {
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"attackVector": "NETWORK",
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"attackComplexity": "LOW",
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"attackRequirements": "PRESENT",
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"privilegesRequired": "NONE",
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"userInteraction": "NONE",
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"vulnConfidentialityImpact": "HIGH",
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"subConfidentialityImpact": "NONE",
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"vulnIntegrityImpact": "HIGH",
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"subIntegrityImpact": "NONE",
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"vulnAvailabilityImpact": "NONE",
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"subAvailabilityImpact": "NONE",
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"exploitMaturity": "NOT_DEFINED",
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"Safety": "NOT_DEFINED",
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"Automatable": "NOT_DEFINED",
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"Recovery": "NOT_DEFINED",
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"valueDensity": "NOT_DEFINED",
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"vulnerabilityResponseEffort": "NOT_DEFINED",
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"providerUrgency": "NOT_DEFINED",
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"version": "4.0",
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"baseSeverity": "CRITICAL",
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"baseScore": 9.1,
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"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
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}
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}
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],
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"credits": [
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{
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"lang": "en",
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"value": "Discovered by Claude, Anthropic's AI assistant, and triaged by the Anthropic security team in collaboration with Anthropic Research.",
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"type": "finder"
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}
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],
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"source": {
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"discovery": "EXTERNAL"
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},
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"x_generator": {
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"engine": "Claude Opus 5.5"
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},
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"x_antReportIds": [
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"ANT-2026-4R53846M",
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"ANT-2026-HJ0G8FQ5"
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]
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},
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"adp": [
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{
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"metrics": [
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{
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"other": {
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"type": "ssvc",
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"content": {
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"timestamp": "2026-10-02T19:06:30.758087Z",
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"id": "CVE-2026-63569",
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"options": [
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{
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"Exploitation": "none"
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},
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{
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"Automatable": "yes"
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},
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{
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"Technical Impact": "total"
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}
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],
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"role": "CISA Coordinator",
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"version": "2.0.3"
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}
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}
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}
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],
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"title": "CISA ADP Vulnrichment",
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"providerMetadata": {
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"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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"shortName": "CISA-ADP",
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"dateUpdated": "2026-10-02T19:07:59.005Z"
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}
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}
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]
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}
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} |