{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2023-52523",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2023-52523",
    "idYear": 2023,
    "status": "PUBLISHED",
    "publishedAt": "2024-03-02T21:52:30.351Z",
    "updatedAt": "2026-08-05T09:10:23.650Z",
    "importedAt": "2026-10-24T01:57:03.413Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "bpf, sockmap: Reject sk_msg egress redirects to non-TCP sockets",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Reject sk_msg egress redirects to non-TCP sockets\n\nWith a SOCKMAP/SOCKHASH map and an sk_msg program user can steer messages\nsent from one TCP socket (s1) to actually egress from another TCP\nsocket (s2):\n\ntcp_bpf_sendmsg(s1)\t\t// = sk_prot->sendmsg\n  tcp_bpf_send_verdict(s1)\t// __SK_REDIRECT case\n    tcp_bpf_sendmsg_redir(s2)\n      tcp_bpf_push_locked(s2)\n\ttcp_bpf_push(s2)\n\t  tcp_rate_check_app_limited(s2) // expects tcp_sock\n\t  tcp_sendmsg_locked(s2)\t // ditto\n\nThere is a hard-coded assumption in the call-chain, that the egress\nsocket (s2) is a TCP socket.\n\nHowever in commit 122e6c79efe1 (\"sock_map: Update sock type checks for\nUDP\") we have enabled redirects to non-TCP sockets. This was done for the\nsake of BPF sk_skb programs. There was no indention to support sk_msg\nsend-to-egress use case.\n\nAs a result, attempts to send-to-egress through a non-TCP socket lead to a\ncrash due to invalid downcast from sock to tcp_sock:\n\n BUG: kernel NULL pointer dereference, address: 000000000000002f\n ...\n Call Trace:\n  <TASK>\n  ? show_regs+0x60/0x70\n  ? __die+0x1f/0x70\n  ? page_fault_oops+0x80/0x160\n  ? do_user_addr_fault+0x2d7/0x800\n  ? rcu_is_watching+0x11/0x50\n  ? exc_page_fault+0x70/0x1c0\n  ? asm_exc_page_fault+0x27/0x30\n  ? tcp_tso_segs+0x14/0xa0\n  tcp_write_xmit+0x67/0xce0\n  __tcp_push_pending_frames+0x32/0xf0\n  tcp_push+0x107/0x140\n  tcp_sendmsg_locked+0x99f/0xbb0\n  tcp_bpf_push+0x19d/0x3a0\n  tcp_bpf_sendmsg_redir+0x55/0xd0\n  tcp_bpf_send_verdict+0x407/0x550\n  tcp_bpf_sendmsg+0x1a1/0x390\n  inet_sendmsg+0x6a/0x70\n  sock_sendmsg+0x9d/0xc0\n  ? sockfd_lookup_light+0x12/0x80\n  __sys_sendto+0x10e/0x160\n  ? syscall_enter_from_user_mode+0x20/0x60\n  ? __this_cpu_preempt_check+0x13/0x20\n  ? lockdep_hardirqs_on+0x82/0x110\n  __x64_sys_sendto+0x1f/0x30\n  do_syscall_64+0x38/0x90\n  entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nReject selecting a non-TCP sockets as redirect target from a BPF sk_msg\nprogram to prevent the crash. When attempted, user will receive an EACCES\nerror from send/sendto/sendmsg() syscall.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "122e6c79efe1c25816118aca9cfabe54e99c2432",
              "status": "affected",
              "versionType": "git",
              "lessThan": "bc8b89b6963803a123f64aa9494155a037b3d728"
            },
            {
              "version": "122e6c79efe1c25816118aca9cfabe54e99c2432",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b8f97e47b6fb84fcf2f5a22e725eefb6cf5070c2"
            },
            {
              "version": "122e6c79efe1c25816118aca9cfabe54e99c2432",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ded6e448028f0f91b6af35985afca01fa02a9089"
            },
            {
              "version": "122e6c79efe1c25816118aca9cfabe54e99c2432",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b80e31baa43614e086a9d29dc1151932b1bd7fc5"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.13",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.13"
            },
            {
              "version": "5.15.135",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.57",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.5.7",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.5.*"
            },
            {
              "version": "6.6",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}