{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49325", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-02-26T02:08:31.538Z", "datePublished": "2025-02-26T02:10:48.158Z", "dateUpdated": "2026-08-05T08:54:43.711Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:54:43.711Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: add accessors to read/set tp->snd_cwnd\n\nWe had various bugs over the years with code\nbreaking the assumption that tp->snd_cwnd is greater\nthan zero.\n\nLately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added\nin commit 8b8a321ff72c (\"tcp: fix zero cwnd in tcp_cwnd_reduction\")\ncan trigger, and without a repro we would have to spend\nconsiderable time finding the bug.\n\nInstead of complaining too late, we want to catch where\nand when tp->snd_cwnd is set to an illegal value." } ], "metrics": [ { "cvssV3_1": { "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" }, "scenarios": [ { "lang": "en", "value": "AV:N - Zero snd_cwnd arises in TCP congestion/MTU-probe paths reached from tcp_rcv_established → tcp_ack → tcp_clean_rtx_queue while processing inbound ACKs, so a remote TCP peer triggers it via ordinary network packets.\nAC:L - A remote peer on a data-heavy connection can shrink cwnd (loss/ECN) and deliver the ACKs that enter cwnd-reduction or probe-success; those peer-side conditions are attacker-controlled, and MTU probing is enabled in realistic deployments.\nPR:N - Exploitation requires only exchanging TCP segments on an established connection to a listening service; no authentication or local privileges are needed.\nUI:N - No victim user action is required beyond an already-running TCP endpoint that sends data and processes peer ACKs.\nS:U - Impact stays within the host kernel TCP/congestion-control authority with no VM escape, IOMMU bypass, or other cross-boundary scope change.\nC:N - The defect only allows snd_cwnd to become zero and trip assertions/divides; it does not corrupt memory or disclose kernel or user data.\nI:N - There is no write primitive, type confusion, or control-flow hijack—only an illegal congestion-window value leading to WARN/div0/BUG paths.\nA:H - Zero snd_cwnd triggers WARN_ON_ONCE(!prior_cwnd), BUG_ON(cwnd <= in_flight), and divide-by-zero in congestion control, causing kernel oops/panic and full host DoS." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/tcp.h", "include/trace/events/tcp.h", "net/core/filter.c", "net/ipv4/tcp.c", "net/ipv4/tcp_bbr.c", "net/ipv4/tcp_bic.c", "net/ipv4/tcp_cdg.c", "net/ipv4/tcp_cong.c", "net/ipv4/tcp_cubic.c", "net/ipv4/tcp_dctcp.c", "net/ipv4/tcp_highspeed.c", "net/ipv4/tcp_htcp.c", "net/ipv4/tcp_hybla.c", "net/ipv4/tcp_illinois.c", "net/ipv4/tcp_input.c", "net/ipv4/tcp_ipv4.c", "net/ipv4/tcp_lp.c", "net/ipv4/tcp_metrics.c", "net/ipv4/tcp_nv.c", "net/ipv4/tcp_output.c", "net/ipv4/tcp_rate.c", "net/ipv4/tcp_scalable.c", "net/ipv4/tcp_vegas.c", "net/ipv4/tcp_veno.c", "net/ipv4/tcp_westwood.c", "net/ipv4/tcp_yeah.c", "net/ipv6/tcp_ipv6.c" ], "versions": [ { "version": "5d424d5a674f782d0659a3b66d951f412901faee", "lessThan": "3308676ec525901bf1656014003c443a60730a04", "status": "affected", "versionType": "git" }, { "version": "5d424d5a674f782d0659a3b66d951f412901faee", "lessThan": "5aba0ad44fb4a7fb78c5076c313456de199a3c29", "status": "affected", "versionType": "git" }, { "version": "5d424d5a674f782d0659a3b66d951f412901faee", "lessThan": "41e191fe72282e193a7744e2fc1786b23156c9e4", "status": "affected", "versionType": "git" }, { "version": "5d424d5a674f782d0659a3b66d951f412901faee", "lessThan": "40570375356c874b1578e05c1dcc3ff7c1322dbe", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/tcp.h", "include/trace/events/tcp.h", "net/core/filter.c", "net/ipv4/tcp.c", "net/ipv4/tcp_bbr.c", "net/ipv4/tcp_bic.c", "net/ipv4/tcp_cdg.c", "net/ipv4/tcp_cong.c", "net/ipv4/tcp_cubic.c", "net/ipv4/tcp_dctcp.c", "net/ipv4/tcp_highspeed.c", "net/ipv4/tcp_htcp.c", "net/ipv4/tcp_hybla.c", "net/ipv4/tcp_illinois.c", "net/ipv4/tcp_input.c", "net/ipv4/tcp_ipv4.c", "net/ipv4/tcp_lp.c", "net/ipv4/tcp_metrics.c", "net/ipv4/tcp_nv.c", "net/ipv4/tcp_output.c", "net/ipv4/tcp_rate.c", "net/ipv4/tcp_scalable.c", "net/ipv4/tcp_vegas.c", "net/ipv4/tcp_veno.c", "net/ipv4/tcp_westwood.c", "net/ipv4/tcp_yeah.c", "net/ipv6/tcp_ipv6.c" ], "versions": [ { "version": "2.6.17", "status": "affected" }, { "version": "0", "lessThan": "2.6.17", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.47", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.17.15", "lessThanOrEqual": "5.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.18.4", "lessThanOrEqual": "5.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.19", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "5.15.47" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "5.17.15" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "5.18.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "5.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3308676ec525901bf1656014003c443a60730a04" }, { "url": "https://git.kernel.org/stable/c/5aba0ad44fb4a7fb78c5076c313456de199a3c29" }, { "url": "https://git.kernel.org/stable/c/41e191fe72282e193a7744e2fc1786b23156c9e4" }, { "url": "https://git.kernel.org/stable/c/40570375356c874b1578e05c1dcc3ff7c1322dbe" } ], "title": "tcp: add accessors to read/set tp->snd_cwnd", "x_generator": { "engine": "bippy-1.2.0" } } } }