Quiche
Monthly
Cloudflare quiche was discovered to be vulnerable to an infinite loop when sending packets containing RETIRE_CONNECTION_ID frames. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Cloudflare quiche, a QUIC protocol implementation, contains a congestion control vulnerability (CVE-2025-4821) where an unauthenticated remote attacker can manipulate ACK frames to artificially inflate the congestion window beyond safe limits, causing excessive data transmission rates and potential denial of service through integer overflow panics. The vulnerability affects quiche versions prior to 0.24.4. While the CVSS score is 7.5 (high severity with network attack vector and no privileges required), real-world exploitation requires completing a QUIC handshake and active manipulation, limiting opportunistic exploitation.
Impact 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. 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. Patches quiche 0.24.4 is the earliest version containing the fix for this issue.
Cloudflare quiche was discovered to be vulnerable to an infinite loop when sending packets containing RETIRE_CONNECTION_ID frames. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Cloudflare quiche, a QUIC protocol implementation, contains a congestion control vulnerability (CVE-2025-4821) where an unauthenticated remote attacker can manipulate ACK frames to artificially inflate the congestion window beyond safe limits, causing excessive data transmission rates and potential denial of service through integer overflow panics. The vulnerability affects quiche versions prior to 0.24.4. While the CVSS score is 7.5 (high severity with network attack vector and no privileges required), real-world exploitation requires completing a QUIC handshake and active manipulation, limiting opportunistic exploitation.
Impact 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. 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. Patches quiche 0.24.4 is the earliest version containing the fix for this issue.