{"id":"CVE-2024-44945","state":"PUBLISHED","title":"netfilter: nfnetlink: Initialise extack before use in ACKs","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink: Initialise extack before use in ACKs\n\nAdd missing extack initialisation when ACKing BATCH_BEGIN and BATCH_END.","publishedAt":"2024-08-31T06:23:32.842Z","updatedAt":"2026-08-05T11:37:12.719Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bf2ac490d28c21a349e9eef81edc45320fca4a3c","status":"affected","lessThan":"3e03b536d9454c5802168b9e85248d456d3ff6a3","versionType":"git"},{"version":"bf2ac490d28c21a349e9eef81edc45320fca4a3c","status":"affected","lessThan":"d1a7b382a9d3f0f3e5a80e0be2991c075fa4f618","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nfnetlink.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","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/netfilter/nfnetlink.c"]}],"references":["https://git.kernel.org/stable/c/3e03b536d9454c5802168b9e85248d456d3ff6a3","https://git.kernel.org/stable/c/d1a7b382a9d3f0f3e5a80e0be2991c075fa4f618"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/44xxx/CVE-2024-44945.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-44945","state":"PUBLISHED","datePublished":"2024-08-31T06:23:32.842Z","dateUpdated":"2026-08-05T11:37:12.719Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-08-21T05:34:56.665Z"},"containers":{"cna":{"title":"netfilter: nfnetlink: Initialise extack before use in ACKs","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink: Initialise extack before use in ACKs\n\nAdd missing extack initialisation when ACKing BATCH_BEGIN and BATCH_END."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bf2ac490d28c21a349e9eef81edc45320fca4a3c","status":"affected","lessThan":"3e03b536d9454c5802168b9e85248d456d3ff6a3","versionType":"git"},{"version":"bf2ac490d28c21a349e9eef81edc45320fca4a3c","status":"affected","lessThan":"d1a7b382a9d3f0f3e5a80e0be2991c075fa4f618","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nfnetlink.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","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/netfilter/nfnetlink.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3e03b536d9454c5802168b9e85248d456d3ff6a3"},{"url":"https://git.kernel.org/stable/c/d1a7b382a9d3f0f3e5a80e0be2991c075fa4f618"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable code is reached only through a `NETLINK_NETFILTER` socket via `sendmsg()`, i.e. a local netlink/syscall interface. Per kernel scoring guidance netfilter/nfnetlink netlink paths are Local.\nAC:L - The attacker fully controls every precondition: it enables `NETLINK_EXT_ACK` on its own socket and sends a well-formed `BATCH_BEGIN|NLM_F_ACK` + `BATCH_END` batch, which deterministically reaches `nfnl_err_add()` with the uninitialized `extack` and delivers it. Stack contents at that frame offset can be groomed by preceding syscalls, so no condition lies outside the attacker's influence.\nPR:L - `nfnetlink_rcv()` requires `CAP_NET_ADMIN` only via `netlink_net_capable()`, which is evaluated against the netns owner's user namespace, so any unprivileged user obtains it with `unshare -Urn`. The nf_tables subsystem is module-autoloaded on demand from that namespace.\nUI:N - The attacker triggers the entire sequence from its own process with socket/sendmsg calls; no victim action or cooperation is involved.\nS:U - The uninitialized read and the resulting disclosure/crash occur entirely within the kernel's own security authority, with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - `netlink_ack_tlv_fill()` does `nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)` on an uninitialized pointer, copying kernel memory at an attacker-groomable address straight back to userspace, and the uninitialized `cookie_len` (up to 255 vs. a 20-byte array) additionally leaks ~130 bytes past the `nfnl_err` slab object. This is an attacker-directed kernel memory read primitive, defeating KASLR and exposing arbitrary kernel data.\nI:N - The defect is a pure use of uninitialized memory — every affected field is only read and serialized into a freshly allocated reply skb, whose `nla_put` calls are tailroom-checked. No kernel memory is written or corrupted, so no modification primitive arises.\nA:H - `strlen()` on the uninitialized `_msg` pointer dereferences a wild address, producing a page-fault oops, and the out-of-bounds `cookie_len` read triggers a KASAN slab-out-of-bounds report (panic with panic_on_warn/KASAN panic). The trigger is cheap and repeatable, so an unprivileged user can crash the kernel at will."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:37:12.719Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"6.10.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"6.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-44945","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T15:27:09.691209Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-12T17:33:04.018Z"}}]}}}