Debian DLA-1730-4 : libssh2 regression update

2019-03-27T00:00:00
ID DEBIAN_DLA-1730.NASL
Type nessus
Reporter This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2019-03-27T00:00:00

Description

Several more boundary checks have been backported to libssh2's src/sftp.c. Furthermore, all boundary checks in src/sftp.c now result in an LIBSSH2_ERROR_BUFFER_TOO_SMALL error code, rather than a LIBSSH2_ERROR_ OUT_OF_BOUNDARY error code.

As a side note, it was discovered that libssh2's SFTP implementation from Debian jessie only works well against OpenSSH SFTP servers from Debian wheezy, tests against newer OpenSSH versions (such as available in Debian jessie and beyond) interim-fail with SFTP protocol error 'Error opening remote file'. Operation might continue after this error, this depends on application implementations.

For Debian 8 'Jessie', this problem has been fixed in version 1.4.3-4.1+deb8u5.

We recommend that you upgrade your libssh2 packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

                                        
                                            #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-1730-4. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(123135);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/09/23");

  script_cve_id("CVE-2019-3860");

  script_name(english:"Debian DLA-1730-4 : libssh2 regression update");
  script_summary(english:"Checks dpkg output for the updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Debian host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Several more boundary checks have been backported to libssh2's
src/sftp.c. Furthermore, all boundary checks in src/sftp.c now result
in an LIBSSH2_ERROR_BUFFER_TOO_SMALL error code, rather than a
LIBSSH2_ERROR_ OUT_OF_BOUNDARY error code.

As a side note, it was discovered that libssh2's SFTP implementation
from Debian jessie only works well against OpenSSH SFTP servers from
Debian wheezy, tests against newer OpenSSH versions (such as available
in Debian jessie and beyond) interim-fail with SFTP protocol error
'Error opening remote file'. Operation might continue after this
error, this depends on application implementations.

For Debian 8 'Jessie', this problem has been fixed in version
1.4.3-4.1+deb8u5.

We recommend that you upgrade your libssh2 packages.

NOTE: Tenable Network Security has extracted the preceding description
block directly from the DLA security advisory. Tenable has attempted
to automatically clean and format it as much as possible without
introducing additional issues."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://lists.debian.org/debian-lts-announce/2019/07/msg00028.html"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/jessie/libssh2"
  );
  script_set_attribute(attribute:"solution", value:"Upgrade the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:P");
  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:N/UI:N/S:U/C:H/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh2-1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh2-1-dbg");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libssh2-1-dev");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/03/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/07/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/03/27");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Debian Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("debian_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;
if (deb_check(release:"8.0", prefix:"libssh2-1", reference:"1.4.3-4.1+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"libssh2-1-dbg", reference:"1.4.3-4.1+deb8u5")) flag++;
if (deb_check(release:"8.0", prefix:"libssh2-1-dev", reference:"1.4.3-4.1+deb8u5")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");