Cisco Unity Connection Remote Code Execution Vulnerability (regreSSHion) (cisco-sa-openssh-rce-2024)

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

include('compat.inc');

if (description)
{
  script_id(314171);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/12");

  script_cve_id("CVE-2024-6387");
  script_xref(name:"CISCO-BUG-ID", value:"CSCwk63494");
  script_xref(name:"CISCO-SA", value:"cisco-sa-openssh-rce-2024");
  script_xref(name:"IAVA", value:"2024-A-0375-S");

  script_name(english:"Cisco Unity Connection Remote Code Execution Vulnerability (regreSSHion) (cisco-sa-openssh-rce-2024)");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version, Cisco Unity Connection is affected by a vulnerability.

  - A remote code execution vulnerability exists in Cisco Unity Connection due to a signal handler race condition found 
    in sshd, where a client does not authenticate within LoginGraceTime seconds, after which the sshd SIGALRM handler is 
    called asynchronously. An unauthenticated, remote attacker can exploit this to call various functions that are not
    async-signal-safe with root privileges. (CVE-2024-6387)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.");
  # https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-openssh-rce-2024
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1ac35fe1");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwk63494");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID CSCwk63494.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2024-6387");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2024/07/01");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/07/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/05/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:unity_connection");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CISCO");

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

  script_dependencies("cisco_uc_version.nasl");
  script_require_keys("installed_sw/Cisco VOSS Unity");

  exit(0);
}

include('vcf.inc');

app_info = vcf::get_app_info(app: 'Cisco VOSS Unity');

# Cisco seems to follow a naming convention that would suggest the COP will be named after the CVE.
# Adding logic to catch this in cases where the customer hotpatched but never fully upgraded to a fixed version.
var version_active = get_kb_item('Host/Cisco/show_version_active');
if ('CVE-2024-6387' >< version_active)
  audit(AUDIT_HOST_NOT, 'affected due to presence of hotfix');

var constraints= [
  {'min_version': '14.0.1.14900.30', 'max_version': '14.999','fixed_display': 'See vendor advisory'},
  {'min_version': '15.0', 'fixed_version': '15.0.1.12900.234'}
];

vcf::check_version_and_report(
  app_info         : app_info,
  constraints      : constraints,
  severity         : SECURITY_HOLE,
  require_paranoia : TRUE
);