Linux Distros Unpatched Vulnerability : CVE-2026-48858

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

include('compat.inc');

if (description)
{
  script_id(320497);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/11");

  script_cve_id("CVE-2026-48858");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2026-48858");

  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.

  - Server-Side Request Forgery (SSRF) vulnerability in Erlang/OTP ftp (ftp_internal module) allows FTP bounce
    attacks and SSRF via an unvalidated PASV response IP address. The ftp_internal:handle_ctrl_result/2 PASV
    handler (mode=passive, ipfamily=inet, ftp_extension=false) extracts the IP address from the server's 227
    response and passes it directly to gen_tcp:connect/4 without validating it against the control connection
    peer address. The adjacent EPSV handlers correctly call peername(CSock) to derive the IP from the control
    connection, but the PASV handler does not. A malicious or compromised FTP server can redirect the client's
    data connection to an arbitrary internal host and port. On read operations (ftp:ls/1,2, ftp:nlist/1,2,
    ftp:recv/2,3), data from the redirected target is returned to the caller. On write operations
    (ftp:send/2,3, ftp:append/2,3), file content is sent to the redirected target. This enables SSRF against
    internal hosts, cloud metadata endpoints, and FTP bounce attacks against third-party hosts. The vulnerable
    path is the default configuration (mode=passive, ipfamily=inet, ftp_extension=false). RFC 2577 section 3
    explicitly recommends validating the PASV response IP against the control connection peer. The ftp
    application is deprecated and scheduled for removal in OTP-30. This vulnerability is associated with
    program files lib/inets/src/ftp/ftp_internal.erl (inets 5.10.4 through 6.5, OTP 17.4 through 20.3) and
    lib/ftp/src/ftp_internal.erl (ftp 1.0 and later, OTP 21.0 and later). This issue affects OTP from OTP 17.4
    before 29.0.2, 28.5.0.2 and 27.3.4.13 corresponding to inets from 5.10.4 before 7.0 and ftp from 1.0
    before 1.2.6, 1.2.4.1 and 1.2.3.1. (CVE-2026-48858)

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-2026-48858");
  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:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-48858");

  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:"2026/06/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/11");

  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:"cpe:/o:debian:debian_linux:13.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:erlang");
  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", "Host/OS/Debian Linux-13", "Host/OS/Debian Linux-14");

  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": "erlang"},
          {"reference": "erlang-asn1"},
          {"reference": "erlang-base"},
          {"reference": "erlang-common-test"},
          {"reference": "erlang-crypto"},
          {"reference": "erlang-debugger"},
          {"reference": "erlang-dev"},
          {"reference": "erlang-dialyzer"},
          {"reference": "erlang-diameter"},
          {"reference": "erlang-doc"},
          {"reference": "erlang-edoc"},
          {"reference": "erlang-eldap"},
          {"reference": "erlang-erl-docgen"},
          {"reference": "erlang-et"},
          {"reference": "erlang-eunit"},
          {"reference": "erlang-examples"},
          {"reference": "erlang-ftp"},
          {"reference": "erlang-inets"},
          {"reference": "erlang-jinterface"},
          {"reference": "erlang-manpages"},
          {"reference": "erlang-megaco"},
          {"reference": "erlang-mnesia"},
          {"reference": "erlang-mode"},
          {"reference": "erlang-nox"},
          {"reference": "erlang-observer"},
          {"reference": "erlang-odbc"},
          {"reference": "erlang-os-mon"},
          {"reference": "erlang-parsetools"},
          {"reference": "erlang-public-key"},
          {"reference": "erlang-reltool"},
          {"reference": "erlang-runtime-tools"},
          {"reference": "erlang-snmp"},
          {"reference": "erlang-src"},
          {"reference": "erlang-ssh"},
          {"reference": "erlang-ssl"},
          {"reference": "erlang-syntax-tools"},
          {"reference": "erlang-tftp"},
          {"reference": "erlang-tools"},
          {"reference": "erlang-wx"},
          {"reference": "erlang-x11"},
          {"reference": "erlang-xmerl"}
        ]
      }
    ]
  },
  "Debian Linux-11": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "11",
        "pkgs": [
          {"reference": "erlang"},
          {"reference": "erlang-asn1"},
          {"reference": "erlang-base"},
          {"reference": "erlang-base-hipe"},
          {"reference": "erlang-common-test"},
          {"reference": "erlang-crypto"},
          {"reference": "erlang-debugger"},
          {"reference": "erlang-dev"},
          {"reference": "erlang-dialyzer"},
          {"reference": "erlang-diameter"},
          {"reference": "erlang-doc"},
          {"reference": "erlang-edoc"},
          {"reference": "erlang-eldap"},
          {"reference": "erlang-erl-docgen"},
          {"reference": "erlang-et"},
          {"reference": "erlang-eunit"},
          {"reference": "erlang-examples"},
          {"reference": "erlang-ftp"},
          {"reference": "erlang-inets"},
          {"reference": "erlang-jinterface"},
          {"reference": "erlang-manpages"},
          {"reference": "erlang-megaco"},
          {"reference": "erlang-mnesia"},
          {"reference": "erlang-mode"},
          {"reference": "erlang-nox"},
          {"reference": "erlang-observer"},
          {"reference": "erlang-odbc"},
          {"reference": "erlang-os-mon"},
          {"reference": "erlang-parsetools"},
          {"reference": "erlang-public-key"},
          {"reference": "erlang-reltool"},
          {"reference": "erlang-runtime-tools"},
          {"reference": "erlang-snmp"},
          {"reference": "erlang-src"},
          {"reference": "erlang-ssh"},
          {"reference": "erlang-ssl"},
          {"reference": "erlang-syntax-tools"},
          {"reference": "erlang-tftp"},
          {"reference": "erlang-tools"},
          {"reference": "erlang-wx"},
          {"reference": "erlang-x11"},
          {"reference": "erlang-xmerl"}
        ]
      }
    ]
  },
  "Debian Linux-13": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "13",
        "pkgs": [
          {"reference": "erlang"},
          {"reference": "erlang-asn1"},
          {"reference": "erlang-base"},
          {"reference": "erlang-common-test"},
          {"reference": "erlang-crypto"},
          {"reference": "erlang-debugger"},
          {"reference": "erlang-dev"},
          {"reference": "erlang-dialyzer"},
          {"reference": "erlang-diameter"},
          {"reference": "erlang-doc"},
          {"reference": "erlang-edoc"},
          {"reference": "erlang-eldap"},
          {"reference": "erlang-et"},
          {"reference": "erlang-eunit"},
          {"reference": "erlang-examples"},
          {"reference": "erlang-ftp"},
          {"reference": "erlang-inets"},
          {"reference": "erlang-jinterface"},
          {"reference": "erlang-megaco"},
          {"reference": "erlang-mnesia"},
          {"reference": "erlang-mode"},
          {"reference": "erlang-nox"},
          {"reference": "erlang-observer"},
          {"reference": "erlang-odbc"},
          {"reference": "erlang-os-mon"},
          {"reference": "erlang-parsetools"},
          {"reference": "erlang-public-key"},
          {"reference": "erlang-reltool"},
          {"reference": "erlang-runtime-tools"},
          {"reference": "erlang-snmp"},
          {"reference": "erlang-src"},
          {"reference": "erlang-ssh"},
          {"reference": "erlang-ssl"},
          {"reference": "erlang-syntax-tools"},
          {"reference": "erlang-tftp"},
          {"reference": "erlang-tools"},
          {"reference": "erlang-wx"},
          {"reference": "erlang-x11"},
          {"reference": "erlang-xmerl"}
        ]
      }
    ]
  },
  "Debian Linux-14": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14",
        "pkgs": [
          {"reference": "erlang"},
          {"reference": "erlang-asn1"},
          {"reference": "erlang-base"},
          {"reference": "erlang-common-test"},
          {"reference": "erlang-crypto"},
          {"reference": "erlang-debugger"},
          {"reference": "erlang-dev"},
          {"reference": "erlang-dialyzer"},
          {"reference": "erlang-diameter"},
          {"reference": "erlang-doc"},
          {"reference": "erlang-edoc"},
          {"reference": "erlang-eldap"},
          {"reference": "erlang-et"},
          {"reference": "erlang-eunit"},
          {"reference": "erlang-examples"},
          {"reference": "erlang-ftp"},
          {"reference": "erlang-inets"},
          {"reference": "erlang-jinterface"},
          {"reference": "erlang-megaco"},
          {"reference": "erlang-mnesia"},
          {"reference": "erlang-mode"},
          {"reference": "erlang-nox"},
          {"reference": "erlang-observer"},
          {"reference": "erlang-odbc"},
          {"reference": "erlang-os-mon"},
          {"reference": "erlang-parsetools"},
          {"reference": "erlang-public-key"},
          {"reference": "erlang-reltool"},
          {"reference": "erlang-runtime-tools"},
          {"reference": "erlang-snmp"},
          {"reference": "erlang-src"},
          {"reference": "erlang-ssh"},
          {"reference": "erlang-ssl"},
          {"reference": "erlang-syntax-tools"},
          {"reference": "erlang-tftp"},
          {"reference": "erlang-tools"},
          {"reference": "erlang-wx"},
          {"reference": "erlang-x11"},
          {"reference": "erlang-xmerl"}
        ]
      }
    ]
  }
};

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');
}