{"id":"CVE-2024-45009","state":"PUBLISHED","title":"mptcp: pm: only decrement add_addr_accepted for MPJ req","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: only decrement add_addr_accepted for MPJ req\n\nAdding the following warning ...\n\n  WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)\n\n... before decrementing the add_addr_accepted counter helped to find a\nbug when running the \"remove single subflow\" subtest from the\nmptcp_join.sh selftest.\n\nRemoving a 'subflow' endpoint will first trigger a RM_ADDR, then the\nsubflow closure. Before this patch, and upon the reception of the\nRM_ADDR, the other peer will then try to decrement this\nadd_addr_accepted. That's not correct because the attached subflows have\nnot been created upon the reception of an ADD_ADDR.\n\nA way to solve that is to decrement the counter only if the attached\nsubflow was an MP_JOIN to a remote id that was not 0, and initiated by\nthe host receiving the RM_ADDR.","publishedAt":"2024-09-11T15:13:47.719Z","updatedAt":"2026-08-05T11:37:39.508Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"35b31f5549ede4070566b949781e83495906b43d","versionType":"git"},{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"85b866e4c4e63a1d7afb58f1e24273caad03d0b7","versionType":"git"},{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"d20bf2c96d7ffd171299b32f562f70e5bf5dc608","versionType":"git"},{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"2060f1efab370b496c4903b840844ecaff324c3c","versionType":"git"},{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"1c1f721375989579e46741f59523e39ec9b2a9bd","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/pm_netlink.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.15.167","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.107","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.48","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.7","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/pm_netlink.c"]}],"references":["https://git.kernel.org/stable/c/35b31f5549ede4070566b949781e83495906b43d","https://git.kernel.org/stable/c/85b866e4c4e63a1d7afb58f1e24273caad03d0b7","https://git.kernel.org/stable/c/d20bf2c96d7ffd171299b32f562f70e5bf5dc608","https://git.kernel.org/stable/c/2060f1efab370b496c4903b840844ecaff324c3c","https://git.kernel.org/stable/c/1c1f721375989579e46741f59523e39ec9b2a9bd","https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/45xxx/CVE-2024-45009.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-45009","state":"PUBLISHED","datePublished":"2024-09-11T15:13:47.719Z","dateUpdated":"2026-08-05T11:37:39.508Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-08-21T05:34:56.679Z"},"containers":{"cna":{"title":"mptcp: pm: only decrement add_addr_accepted for MPJ req","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: only decrement add_addr_accepted for MPJ req\n\nAdding the following warning ...\n\n  WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)\n\n... before decrementing the add_addr_accepted counter helped to find a\nbug when running the \"remove single subflow\" subtest from the\nmptcp_join.sh selftest.\n\nRemoving a 'subflow' endpoint will first trigger a RM_ADDR, then the\nsubflow closure. Before this patch, and upon the reception of the\nRM_ADDR, the other peer will then try to decrement this\nadd_addr_accepted. That's not correct because the attached subflows have\nnot been created upon the reception of an ADD_ADDR.\n\nA way to solve that is to decrement the counter only if the attached\nsubflow was an MP_JOIN to a remote id that was not 0, and initiated by\nthe host receiving the RM_ADDR."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"35b31f5549ede4070566b949781e83495906b43d","versionType":"git"},{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"85b866e4c4e63a1d7afb58f1e24273caad03d0b7","versionType":"git"},{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"d20bf2c96d7ffd171299b32f562f70e5bf5dc608","versionType":"git"},{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"2060f1efab370b496c4903b840844ecaff324c3c","versionType":"git"},{"version":"d0876b2284cf8b34dd214b2d0aa21071c345da59","status":"affected","lessThan":"1c1f721375989579e46741f59523e39ec9b2a9bd","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/pm_netlink.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.15.167","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.107","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.48","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.7","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/pm_netlink.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/35b31f5549ede4070566b949781e83495906b43d"},{"url":"https://git.kernel.org/stable/c/85b866e4c4e63a1d7afb58f1e24273caad03d0b7"},{"url":"https://git.kernel.org/stable/c/d20bf2c96d7ffd171299b32f562f70e5bf5dc608"},{"url":"https://git.kernel.org/stable/c/2060f1efab370b496c4903b840844ecaff324c3c"},{"url":"https://git.kernel.org/stable/c/1c1f721375989579e46741f59523e39ec9b2a9bd"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","baseScore":8.2,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable counter decrement is driven entirely by an RM_ADDR MPTCP option parsed out of a received TCP segment (options.c:1174 → mptcp_pm_rm_addr_received()), so any remote peer of an MPTCP connection can reach it over the network. MPTCP servers (IPPROTO_MPTCP listeners on cloud/mobile/edge systems) accept these from arbitrary internet clients.\nAC:L - The attacker fully controls both the MP_JOIN that creates the non-ADD_ADDR subflow and the subsequent RM_ADDR that removes it, with the address ID chosen by the attacker; no race, memory layout, or victim-side timing is involved. Default settings (kernel path manager, subflows_max=2, accept_subflow=true) suffice, making the underflow deterministic and repeatable.\nPR:N - MPTCP has no authentication layer above TCP — a client connecting to an MPTCP-enabled service, or a malicious server a client connects to, can drive this without any credentials or local account. No capability, namespace, or netlink access is needed anywhere along the path.\nUI:N - Against an MPTCP-enabled listening service the attacker initiates the connection and sends the MP_JOIN and RM_ADDR options itself. No victim action is required beyond the service already running.\nS:U - The corrupted state (msk->pm.add_addr_accepted and pm.accept_addr) and all consequences remain within the kernel networking stack of the affected host. No hypervisor, IOMMU, or sandbox boundary is crossed.\nC:N - The defect is an arithmetic underflow of an internal accounting counter; it yields no out-of-bounds read, no kernel pointer exposure, and no path for reading memory the attacker should not see. Subflows forced open by the bypass still require the connection keys for MP_JOIN, so no session data is disclosed to third parties.\nI:L - A remote unauthenticated peer corrupts kernel path-manager state (counter wraps 0 → 255 and accept_addr is forced true), bypassing the administrator-configured net.mptcp add_addr_accepted limit — including its default value of 0 meaning \"accept none\". This modifies protected kernel state and alters the host's path-management behavior, but grants no arbitrary write or control-flow influence.\nA:H - The underflowed counter defeats the sole resource-protection control on accepted address announcements, letting a remote peer repeatedly cycle MP_JOIN/RM_ADDR to refill the ADD_ADDR budget and drive unbounded attacker-directed subflow and socket creation from the victim. Sustained across many parallel connections this is a plausible resource-exhaustion denial of service, and the higher rating is taken given the uncertainty in bounding it."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:37:39.508Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.15.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.1.107"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.6.48"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.10.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-09-29T15:51:12.192901Z","id":"CVE-2024-45009","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-29T15:51:26.527Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T22:15:15.298Z"}}]}}}