{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-50048","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-06-18T10:57:27.402Z","datePublished":"2025-06-18T11:01:48.893Z","dateUpdated":"2026-08-05T08:57:14.148Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T08:57:14.148Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: possible module reference underflow in error path\n\ndst->ops is set on when nft_expr_clone() fails, but module refcount has\nnot been bumped yet, therefore nft_expr_destroy() leads to module\nreference underflow."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through the local NETLINK_NETFILTER/nf_tables path (NFT_MSG_NEWSETELEM → nft_add_set_elem → nft_set_elem_expr_clone, or dynset init), which requires opening a netlink socket; it is not reachable from remote packet processing.\nAC:L - The attacker fully controls set creation with a stateful clone-capable expression (counter/limit/quota/last/connlimit) and element adds that omit per-element expressions, and can induce the GFP_ATOMIC clone allocation failure via memory pressure, so the underflow is reliably triggerable with no race or luck.\nPR:L - nfnetlink_rcv() gates on netlink_net_capable(skb, CAP_NET_ADMIN) against the network namespace's user_ns, so an ordinary unprivileged user obtains the needed capability via unshare -Urn on default distributions.\nUI:N - The attacker creates the set, induces clone failure, and triggers the destroy/module_put error path entirely from their own process with no victim action required.\nS:U - Impact is confined to the host kernel (module UAF / refcount corruption and privilege escalation within the same OS security authority); no VM, IOMMU, or hypervisor boundary is crossed.\nC:H - The erroneous module_put without a matching get underflows the expression module's refcount so it can be unloaded while set expressions still reference its ops/code, yielding a classic module UAF that enables arbitrary kernel memory disclosure.\nI:H - Premature unload of nft_limit/nft_quota/nft_connlimit (or nf_tables for built-in counter/last) leaves live expression ops pointing into freed module memory that can be sprayed for control-flow hijack; the connlimit path also wrongly calls nf_ct_netns_put, compounding refcount corruption.\nA:H - On connlimit, destroy runs nf_conncount_cache_free(NULL) and NULL-dereferences; on other expressions the module refcount underflow/UAF produces oops/panic, so availability impact is High even without full exploitation."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_tables_api.c"],"versions":[{"version":"8cfd9b0f8515e7c361bba27e2a2684cbd427fe01","lessThan":"b59bee8b05b0e789b5a298cacb09e8aaa3367a29","status":"affected","versionType":"git"},{"version":"8cfd9b0f8515e7c361bba27e2a2684cbd427fe01","lessThan":"1e52e6cfec6342c3d0df47dc3a76724fb3dabf56","status":"affected","versionType":"git"},{"version":"8cfd9b0f8515e7c361bba27e2a2684cbd427fe01","lessThan":"c485c35ff6783ccd12c160fcac6a0e504e83e0bf","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_tables_api.c"],"versions":[{"version":"5.11","status":"affected"},{"version":"0","lessThan":"5.11","status":"unaffected","versionType":"semver"},{"version":"5.15.63","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"5.19.4","lessThanOrEqual":"5.19.*","status":"unaffected","versionType":"semver"},{"version":"6.0","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":"5.11","versionEndExcluding":"5.15.63"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.19.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.0"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/b59bee8b05b0e789b5a298cacb09e8aaa3367a29"},{"url":"https://git.kernel.org/stable/c/1e52e6cfec6342c3d0df47dc3a76724fb3dabf56"},{"url":"https://git.kernel.org/stable/c/c485c35ff6783ccd12c160fcac6a0e504e83e0bf"}],"title":"netfilter: nf_tables: possible module reference underflow in error path","x_generator":{"engine":"bippy-1.2.0"}}}}