EulerOS 2.0 SP13 : proftpd (EulerOS-SA-2026-4183)

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

include('compat.inc');

if (description)
{
  script_id(364976);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/12");

  script_cve_id("CVE-2026-53994", "CVE-2026-63090", "CVE-2026-63091");

  script_name(english:"EulerOS 2.0 SP13 : proftpd (EulerOS-SA-2026-4183)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the proftpd package installed, the EulerOS installation on the remote host is affected by
the following vulnerabilities :

    ProFTPD mod_sftp contains a heap-based buffer overflow reachable by an authenticated SFTP user. The
    fxp_packet_read() function accepts the attacker-supplied 32-bit big-endian SFTP packet length without a
    minimum sanity check. A value of 0 causes an unsigned subtraction elsewhere in the read path to underflow
    to approximately 4 GB. That oversized request reaches the core memory allocator, where the rounded size is
    computed in size_t but passed to new_block() as a 32-bit int; the low 32 bits of 0x100000000 are 0, so
    new_block() returns a small (~512-byte) block while the caller is told it received ~4 GB. The subsequent
    fill loop then streams attacker-controlled bytes past the end of the 544-byte allocation, producing an
    attacker-controlled heap buffer overflow. An authenticated user can crash the per-connection ProFTPD
    session child on demand with a single malformed SFTP packet (packet_len=0 followed by a body greater than
    approximately 544 bytes), producing reliable authenticated remote denial of service. Depending on heap
    layout and adjacent allocations, heap metadata corruption and further consequences beyond denial of
    service may be possible, though only denial of service is demonstrated by the supplied proof of
    concept.(CVE-2026-53994)

    ProFTPD before 1.3.9c and 1.3.10rc3 contains a signed integer overflow vulnerability in the mod_sftp
    module's SCP size-record parser that allows authenticated low-privilege attackers to bypass ASLR by
    sending a crafted file size value of UINT64_MAX, which results in a negative off_t value. Attackers can
    exploit the subsequent conversion to uint32_t, causing an approximately 4 GB requested read length and
    forcing the server to read beyond the end of the SSH channel data and write overread process memory into
    the uploaded file. In tested configurations, the disclosed data contains libc, libcrypto, and PIE pointers
    sufficient to derive their randomized base addresses, thereby bypassing ASLR and enabling reliable
    exploitation of memory corruption vulnerabilities in the same process.(CVE-2026-63091)

    ProFTPD before 1.3.9c and 1.3.10rc3 contains a heap-based buffer overflow vulnerability in the mod_sftp
    module that allows authenticated low-privilege attackers to achieve arbitrary code execution by sending
    crafted SFTP packet fragments exceeding the 16 KB reassembly buffer in the fxp.c component. Attackers can
    supply oversized fragments to trigger an incorrectly conditioned reallocation, corrupt pool freelist
    metadata, overwrite the root_fs BSS global pointer to reference a fake filesystem struct, and redirect
    pr_fsio_stat() to system() via a crafted RENAME request.(CVE-2026-63090)

Tenable has extracted the preceding description block directly from the EulerOS proftpd security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2026-4183
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?3bdc0a31");
  script_set_attribute(attribute:"solution", value:
"Update the affected proftpd packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-53994");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-63090");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/07/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:proftpd");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei Local Security Checks");

  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");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
  script_exclude_keys("Host/EulerOS/uvp_version");

  exit(0);
}

include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var _release = get_kb_item("Host/EulerOS/release");
if (isnull(_release) || _release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (_release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13");

var sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(13)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13");

if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP13", "EulerOS UVP " + uvp);

if (!get_kb_item("Host/EulerOS/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "aarch64" >!< cpu && "x86" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("aarch64" >!< cpu) audit(AUDIT_ARCH_NOT, "aarch64", cpu);

var flag = 0;

var pkgs = [
  "proftpd-1.3.7c-4.h16.eulerosv2r13"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"13", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "proftpd");
}