{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2025-4820","assignerOrgId":"a22f1246-ba21-4bb4-a601-ad51614c1513","state":"PUBLISHED","assignerShortName":"cloudflare","dateReserved":"2025-05-16T11:52:21.636Z","datePublished":"2025-06-18T15:45:49.994Z","dateUpdated":"2025-06-18T18:27:38.799Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","packageName":"cloudflare-quiche","product":"quiche","vendor":"Cloudflare","versions":[{"status":"affected","version":"<0.24.4"}]}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<b>Impact</b><br><br>Cloudflare quiche was discovered to be vulnerable to incorrect congestion window growth, which could cause it to send data at a rate faster than the path might actually support.<br><br>An unauthenticated remote attacker can exploit the vulnerability by first completing a handshake and initiating a congestion-controlled data transfer towards itself. Then, it could manipulate the victim's congestion control state by sending ACK frames exercising an opportunistic ACK attack; see RFC 9000 Section 21.4. The victim could grow the congestion window beyond typical expectations and allow more bytes in flight than the path might really support.<br><div><br></div><div><b>Patches</b></div><br>quiche 0.24.4 is the earliest version containing the fix for this issue."}],"value":"Impact\n\nCloudflare quiche was discovered to be vulnerable to incorrect congestion window growth, which could cause it to send data at a rate faster than the path might actually support.\n\nAn unauthenticated remote attacker can exploit the vulnerability by first completing a handshake and initiating a congestion-controlled data transfer towards itself. Then, it could manipulate the victim's congestion control state by sending ACK frames exercising an opportunistic ACK attack; see RFC 9000 Section 21.4. The victim could grow the congestion window beyond typical expectations and allow more bytes in flight than the path might really support.\n\n\n\nPatches\n\n\nquiche 0.24.4 is the earliest version containing the fix for this issue."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","description":"CWE-770 Allocation of Resources Without Limits or Throttling","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"a22f1246-ba21-4bb4-a601-ad51614c1513","shortName":"cloudflare","dateUpdated":"2025-06-18T15:45:49.994Z"},"references":[{"url":"https://github.com/cloudflare/quiche/security/advisories/GHSA-2v9p-3p3h-w56j"}],"source":{"discovery":"UNKNOWN"},"title":"Incorrect congestion window growth by optimistic ACK","x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2025-06-18T18:27:27.515226Z","id":"CVE-2025-4820","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2025-06-18T18:27:38.799Z"}}]}}