Linux Distros Unpatched Vulnerability : CVE-2026-46132

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(317556);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/29");

  script_cve_id("CVE-2026-46132");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-46132");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - net: rtnetlink: zero ifla_vf_broadcast to avoid stack infoleak in rtnl_fill_vfinfo rtnl_fill_vfinfo()
    declares struct ifla_vf_broadcast on the stack without initialisation: struct ifla_vf_broadcast
    vf_broadcast; The struct contains a single fixed 32-byte field: /* include/uapi/linux/if_link.h */ struct
    ifla_vf_broadcast { __u8 broadcast[32]; }; The function then copies dev->broadcast into it using
    dev->addr_len as the length: memcpy(vf_broadcast.broadcast, dev->broadcast, dev->addr_len); On Ethernet
    devices (the overwhelming majority of SR-IOV NICs) dev->addr_len is 6, so only the first 6 bytes of
    broadcast[] are written. The remaining 26 bytes retain whatever was previously on the kernel stack. The
    full struct is then handed to userspace via: nla_put(skb, IFLA_VF_BROADCAST, sizeof(vf_broadcast),
    &vf_broadcast) leaking up to 26 bytes of uninitialised kernel stack per VF per RTM_GETLINK request,
    repeatable. The other vf_* structs in the same function are explicitly zeroed for exactly this reason -
    see the memset() calls for ivi, vf_vlan_info, node_guid and port_guid a few lines above. vf_broadcast was
    simply missed when it was added. Reachability: any unprivileged local process can open AF_NETLINK /
    NETLINK_ROUTE without capabilities and send RTM_GETLINK with an IFLA_EXT_MASK attribute carrying
    RTEXT_FILTER_VF. The kernel walks each VF and emits IFLA_VF_BROADCAST, leaking 26 bytes of stack per VF
    per request. Stack residue at this call site can include return addresses and transient sensitive data;
    KASAN with stack instrumentation, or KMSAN, will flag the nla_put() when reproduced. Zero the on-stack
    struct before the partial memcpy, matching the existing pattern used for the other vf_* structs in the
    same function. (CVE-2026-46132)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-46132");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-46132");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_unpatched", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/05/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/05/29");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:11.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:12.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:linux");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl", "set_linux_os_id.nasl");
  script_require_keys("Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched", "Host/OS/identifier");
  script_require_ports("Host/OS/Debian Linux-11", "Host/OS/Debian Linux-12");

  exit(0);
}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Debian Linux-12": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "12",
        "pkgs": [
          {"reference": "btrfs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "cdrom-core-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "ext4-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "fat-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "isofs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "jfs-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "kernel-image-6.1.0-47-alpha-generic-di"},
          {"reference": "linux-doc"},
          {"reference": "linux-doc-6.1"},
          {"reference": "linux-headers-6.1.0"},
          {"reference": "linux-source"},
          {"reference": "linux-source-6.1"},
          {"reference": "linux-support-6.1.0"},
          {"reference": "loop-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-shared-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "nic-wireless-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "pata-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "ppp-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-core-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "scsi-nic-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "serial-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "usb-serial-modules-6.1.0-47-alpha-generic-di"},
          {"reference": "xfs-modules-6.1.0-47-alpha-generic-di"}
        ]
      }
    ]
  },
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "bpftool"},
          {"reference": "btrfs-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "cdrom-core-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "hyperv-daemons"},
          {"reference": "kernel-image-5.10.0-32-alpha-generic-di"},
          {"reference": "libcpupower-dev"},
          {"reference": "libcpupower1"},
          {"reference": "linux-bootwrapper-5.10.0"},
          {"reference": "linux-config-5.10"},
          {"reference": "linux-cpupower"},
          {"reference": "linux-doc"},
          {"reference": "linux-doc-5.10"},
          {"reference": "linux-headers-5.10.0"},
          {"reference": "linux-kbuild-5.10"},
          {"reference": "linux-libc-dev"},
          {"reference": "linux-perf"},
          {"reference": "linux-perf-5.10"},
          {"reference": "linux-source"},
          {"reference": "linux-source-5.10"},
          {"reference": "linux-support-5.10.0"},
          {"reference": "loop-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-shared-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "nic-wireless-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "pata-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "ppp-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-core-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "scsi-nic-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "serial-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "usb-serial-modules-5.10.0-32-alpha-generic-di"},
          {"reference": "usbip"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');
var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}