{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-37749", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.937Z", "datePublished": "2025-05-01T12:55:55.316Z", "dateUpdated": "2026-08-05T11:57:13.771Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:57:13.771Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ppp: Add bound checking for skb data on ppp_sync_txmung\n\nEnsure we have enough data in linear buffer from skb before accessing\ninitial bytes. This prevents potential out-of-bounds accesses\nwhen processing short packets.\n\nWhen ppp_sync_txmung receives an incoming package with an empty\npayload:\n(remote) gef➤ p *(struct pppoe_hdr *) (skb->head + skb->network_header)\n$18 = {\n\ttype = 0x1,\n\tver = 0x1,\n\tcode = 0x0,\n\tsid = 0x2,\n length = 0x0,\n\ttag = 0xffff8880371cdb96\n}\n\nfrom the skb struct (trimmed)\n tail = 0x16,\n end = 0x140,\n head = 0xffff88803346f400 \"4\",\n data = 0xffff88803346f416 \":\\377\",\n truesize = 0x380,\n len = 0x0,\n data_len = 0x0,\n mac_len = 0xe,\n hdr_len = 0x0,\n\nit is not safe to access data[2].\n\n[pabeni@redhat.com: fixed subj typo]" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H", "baseScore": 8.2, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable function is reached from `ppp_input()` via `ppp_channel_bridge_input()`, which forwards remotely received PPP frames directly to the sync-tty channel's `start_xmit` before any length validation; the feeding channels include pppol2tp (UDP/IP) and pptp (GRE/IP), both routable across the internet on VPN concentrators. A remote peer sending a PPP payload shorter than 3 bytes triggers the read.\nAC:L - The trigger is fully deterministic and entirely attacker-controlled — emit one PPP frame with a zero-length or 1-2 byte payload; there is no race, no memory-layout requirement, and no state the attacker cannot influence.\nPR:N - PPPoE/PPTP/L2TP session establishment happens before any PPP-layer authentication (LCP/CHAP/PAP), so the malformed frame can be sent by an unauthenticated peer on an established but not-yet-authenticated session. No local account or capability is needed.\nUI:N - The out-of-bounds read occurs during normal packet transmit processing driven entirely by the attacker's inbound frame. No victim action is required.\nS:U - The impact is confined to the kernel's own security authority — a kernel-memory read within the same host. No VM, IOMMU, or sandbox boundary is crossed.\nC:L - The read is strictly bounded to at most 3 bytes past the valid skb data, and those bytes are never transmitted — they only influence the `islcp`/protocol-compression branches, giving an indirect oracle over adjacent (possibly uninitialized) kernel heap contents rather than an arbitrary read primitive.\nI:N - The defect is read-only; `skb_pull()` is length-checked via `skb_pull_inline()` so `skb->len` cannot underflow, and the subsequent `skb_push()` is guarded by an explicit `skb_headroom()` check, leaving no out-of-bounds write or corrupted state.\nA:H - The out-of-bounds access is syzbot-reproducible and trips KASAN/KMSAN, causing an oops or panic on sanitizer-enabled and hardened kernels (panic_on_oops/panic_on_warn), and it can be triggered repeatedly by an unauthenticated remote peer." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ppp/ppp_synctty.c" ], "versions": [ { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "529401c8f12ecc35f9ea5d946d5a5596cf172b48", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "de5a4f0cba58625e88b7bebd88f780c8c0150997", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "99aa698dec342a07125d733e39aab4394b3b7e05", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "b78f2b458f56a5a4d976c8e01c43dbf58d3ea2ca", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "fbaffe8bccf148ece8ad67eb5d7aa852cabf59c8", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "b4c836d33ca888695b2f2665f948bc1b34fbd533", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "1f6eb9fa87a781d5370c0de7794ae242f1a95ee5", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "6e8a6bf43cea4347121ab21bb1ed8d7bef7e732e", "status": "affected", "versionType": "git" }, { "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "aabc6596ffb377c4c9c8f335124b92ea282c9821", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ppp/ppp_synctty.c" ], "versions": [ { "version": "2.6.12", "status": "affected" }, { "version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.293", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.237", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.181", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.135", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.88", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.24", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.12", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14.3", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15", "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": "2.6.12", "versionEndExcluding": "5.4.293" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.10.237" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "5.15.181" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.1.135" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.6.88" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.12.24" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.13.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.14.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.15" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/529401c8f12ecc35f9ea5d946d5a5596cf172b48" }, { "url": "https://git.kernel.org/stable/c/de5a4f0cba58625e88b7bebd88f780c8c0150997" }, { "url": "https://git.kernel.org/stable/c/99aa698dec342a07125d733e39aab4394b3b7e05" }, { "url": "https://git.kernel.org/stable/c/b78f2b458f56a5a4d976c8e01c43dbf58d3ea2ca" }, { "url": "https://git.kernel.org/stable/c/fbaffe8bccf148ece8ad67eb5d7aa852cabf59c8" }, { "url": "https://git.kernel.org/stable/c/b4c836d33ca888695b2f2665f948bc1b34fbd533" }, { "url": "https://git.kernel.org/stable/c/1f6eb9fa87a781d5370c0de7794ae242f1a95ee5" }, { "url": "https://git.kernel.org/stable/c/6e8a6bf43cea4347121ab21bb1ed8d7bef7e732e" }, { "url": "https://git.kernel.org/stable/c/aabc6596ffb377c4c9c8f335124b92ea282c9821" } ], "title": "net: ppp: Add bound checking for skb data on ppp_sync_txmung", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:54:24.795Z" } } ] } }