{"id":"CVE-2023-53570","state":"PUBLISHED","title":"wifi: nl80211: fix integer overflow in nl80211_parse_mbssid_elems()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: nl80211: fix integer overflow in nl80211_parse_mbssid_elems()\n\nnl80211_parse_mbssid_elems() uses a u8 variable num_elems to count the\nnumber of MBSSID elements in the nested netlink attribute attrs, which can\nlead to an integer overflow if a user of the nl80211 interface specifies\n256 or more elements in the corresponding attribute in userspace. The\ninteger overflow can lead to a heap buffer overflow as num_elems determines\nthe size of the trailing array in elems, and this array is thereafter\nwritten to for each element in attrs.\n\nNote that this vulnerability only affects devices with the\nwiphy->mbssid_max_interfaces member set for the wireless physical device\nstruct in the device driver, and can only be triggered by a process with\nCAP_NET_ADMIN capabilities.\n\nFix this by checking for a maximum of 255 elements in attrs.","publishedAt":"2025-10-04T15:17:11.525Z","updatedAt":"2026-08-05T09:14:53.243Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"dc1e3cb8da8b414b37208b2fb6755fef8122504b","status":"affected","lessThan":"e642eb67b8c10dcce758d549cc81564116e0fa49","versionType":"git"},{"version":"dc1e3cb8da8b414b37208b2fb6755fef8122504b","status":"affected","lessThan":"7d09f9f255a5f78578deba5454923072bb53b16c","versionType":"git"},{"version":"dc1e3cb8da8b414b37208b2fb6755fef8122504b","status":"affected","lessThan":"6311071a056272e1e761de8d0305e87cc566f734","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/wireless/nl80211.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.16","versionType":"semver"},{"version":"6.1.46","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.4.11","status":"unaffected","lessThanOrEqual":"6.4.*","versionType":"semver"},{"version":"6.5","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/wireless/nl80211.c"]}],"references":["https://git.kernel.org/stable/c/e642eb67b8c10dcce758d549cc81564116e0fa49","https://git.kernel.org/stable/c/7d09f9f255a5f78578deba5454923072bb53b16c","https://git.kernel.org/stable/c/6311071a056272e1e761de8d0305e87cc566f734"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/53xxx/CVE-2023-53570.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53570","state":"PUBLISHED","datePublished":"2025-10-04T15:17:11.525Z","dateUpdated":"2026-08-05T09:14:53.243Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-10-04T15:14:15.925Z"},"containers":{"cna":{"title":"wifi: nl80211: fix integer overflow in nl80211_parse_mbssid_elems()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: nl80211: fix integer overflow in nl80211_parse_mbssid_elems()\n\nnl80211_parse_mbssid_elems() uses a u8 variable num_elems to count the\nnumber of MBSSID elements in the nested netlink attribute attrs, which can\nlead to an integer overflow if a user of the nl80211 interface specifies\n256 or more elements in the corresponding attribute in userspace. The\ninteger overflow can lead to a heap buffer overflow as num_elems determines\nthe size of the trailing array in elems, and this array is thereafter\nwritten to for each element in attrs.\n\nNote that this vulnerability only affects devices with the\nwiphy->mbssid_max_interfaces member set for the wireless physical device\nstruct in the device driver, and can only be triggered by a process with\nCAP_NET_ADMIN capabilities.\n\nFix this by checking for a maximum of 255 elements in attrs."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"dc1e3cb8da8b414b37208b2fb6755fef8122504b","status":"affected","lessThan":"e642eb67b8c10dcce758d549cc81564116e0fa49","versionType":"git"},{"version":"dc1e3cb8da8b414b37208b2fb6755fef8122504b","status":"affected","lessThan":"7d09f9f255a5f78578deba5454923072bb53b16c","versionType":"git"},{"version":"dc1e3cb8da8b414b37208b2fb6755fef8122504b","status":"affected","lessThan":"6311071a056272e1e761de8d0305e87cc566f734","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/wireless/nl80211.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.16","versionType":"semver"},{"version":"6.1.46","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.4.11","status":"unaffected","lessThanOrEqual":"6.4.*","versionType":"semver"},{"version":"6.5","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/wireless/nl80211.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e642eb67b8c10dcce758d549cc81564116e0fa49"},{"url":"https://git.kernel.org/stable/c/7d09f9f255a5f78578deba5454923072bb53b16c"},{"url":"https://git.kernel.org/stable/c/6311071a056272e1e761de8d0305e87cc566f734"}],"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 vulnerability is triggered by crafting an nl80211 generic-netlink message (NL80211_CMD_START_AP/SET_BEACON/CHANNEL_SWITCH) from local userspace; despite being in the wireless subsystem, no over-the-air frame is involved. Per kernel scoring guidance, netlink-reachable bugs are Local.\nAC:L - The attacker fully and deterministically controls the trigger by placing 256 nested attributes in NL80211_ATTR_MBSSID_ELEMS — no race, no timing, no memory-layout condition outside their influence, and the overflow size and contents are directly tunable via the attribute count and lengths.\nPR:L - The gate is GENL_UNS_ADMIN_PERM, i.e. netlink_ns_capable(net->user_ns, CAP_NET_ADMIN), which an unprivileged user obtains via `unshare -Urn`; mac80211_hwsim's radio-creation command is gated identically and places the new wiphy (with mbssid_max_interfaces = 8) in the caller's netns, giving a complete unprivileged local path.\nUI:N - The attacker performs every step themselves — create/select an AP-capable interface and issue the netlink command — with no action required from any other user or administrator.\nS:U - The heap corruption occurs in kernel slab memory within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - A 4 KB controlled out-of-bounds heap write lets the attacker overwrite adjacent objects' pointers and length fields, which is readily leveraged into arbitrary kernel-memory disclosure, so confidentiality impact is High.\nI:H - This is a large, attacker-sized out-of-bounds heap write with a fully attacker-controlled size_t field per entry, providing a strong slab-corruption primitive suitable for control-flow hijack and privilege escalation.\nA:H - Writing 4096 bytes past an 8-byte kmalloc allocation reliably corrupts slab metadata and neighbouring objects, producing kernel oops/panic and complete loss of availability."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T09:14:53.243Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.1.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.4.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.5"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}