Debian DLA-171-1 : libssh2 security update

2015-03-26T00:00:00
ID DEBIAN_DLA-171.NASL
Type nessus
Reporter Tenable
Modified 2018-07-06T00:00:00

Description

Mariusz Ziulek reported that libssh2, a SSH2 client-side library, was reading and using the SSH_MSG_KEXINIT packet without doing sufficient range checks when negotiating a new SSH session with a remote server. A malicious attacker could man in the middle a real server and cause a client using the libssh2 library to crash (denial of service) or otherwise read and use unintended memory areas in this process.

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.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-171-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(82156);
  script_version("1.5");
  script_cvs_date("Date: 2018/07/06 11:26:06");

  script_cve_id("CVE-2015-1782");
  script_bugtraq_id(73061);

  script_name(english:"Debian DLA-171-1 : libssh2 security 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:
"Mariusz Ziulek reported that libssh2, a SSH2 client-side library, was
reading and using the SSH_MSG_KEXINIT packet without doing sufficient
range checks when negotiating a new SSH session with a remote server.
A malicious attacker could man in the middle a real server and cause a
client using the libssh2 library to crash (denial of service) or
otherwise read and use unintended memory areas in this process.

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/2015/03/msg00008.html"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/squeeze-lts/libssh2"
  );
  script_set_attribute(attribute:"solution", value:"Upgrade the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  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:6.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2015/03/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/03/26");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2015-2018 Tenable Network Security, Inc.");
  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:"6.0", prefix:"libssh2-1", reference:"1.2.6-1+deb6u1")) flag++;
if (deb_check(release:"6.0", prefix:"libssh2-1-dbg", reference:"1.2.6-1+deb6u1")) flag++;
if (deb_check(release:"6.0", prefix:"libssh2-1-dev", reference:"1.2.6-1+deb6u1")) 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");