Vulnerabilities > CVE-2007-4321 - Remote Denial of Service vulnerability in Fail2Ban 0.8

#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Gentoo Linux Security Advisory GLSA 200707-13.
#
# The advisory text is Copyright (C) 2001-2015 Gentoo Foundation, Inc.
# and licensed under the Creative Commons - Attribution / Share Alike 
# license. See http://creativecommons.org/licenses/by-sa/3.0/
#

include("compat.inc");

if (description)
{
  script_id(25809);
  script_version("1.13");
  script_cvs_date("Date: 2019/08/02 13:32:44");

  script_cve_id("CVE-2007-4321");
  script_xref(name:"GLSA", value:"200707-13");

  script_name(english:"GLSA-200707-13 : Fail2ban: Denial of Service");
  script_summary(english:"Checks for updated package(s) in /var/db/pkg");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Gentoo host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"The remote host is affected by the vulnerability described in GLSA-200707-13
(Fail2ban: Denial of Service)

    A vulnerability has been discovered in Fail2ban when parsing log files.
  
Impact :

    A remote attacker could send specially crafted SSH login banners to the
    vulnerable host, which would prevent any ssh connection to the host and
    result in a Denial of Service.
  
Workaround :

    There is no known workaround at this time."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.ossec.net/en/attacking-loganalysis.html#fail2ban"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://security.gentoo.org/glsa/200707-13"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"All Fail2ban users should upgrade to the latest version:
    # emerge --sync
    # emerge --ask --oneshot --verbose '>=net-analyzer/fail2ban-0.8.0-r1'"
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:gentoo:linux:fail2ban");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:gentoo:linux");

  script_set_attribute(attribute:"patch_publication_date", value:"2007/07/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2007/07/30");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2007-2019 Tenable Network Security, Inc.");
  script_family(english:"Gentoo Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Gentoo/release", "Host/Gentoo/qpkg-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("qpkg.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Gentoo/release")) audit(AUDIT_OS_NOT, "Gentoo");
if (!get_kb_item("Host/Gentoo/qpkg-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;

if (qpkg_check(package:"net-analyzer/fail2ban", unaffected:make_list("ge 0.8.0-r1"), vulnerable:make_list("lt 0.8.0-r1"))) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:qpkg_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = qpkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "Fail2ban");
}

#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Debian Security Advisory DSA-1456. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(29903);
  script_version("1.12");
  script_cvs_date("Date: 2019/08/02 13:32:21");

  script_cve_id("CVE-2007-4321");
  script_xref(name:"DSA", value:"1456");

  script_name(english:"Debian DSA-1456-1 : fail2ban - programming error");
  script_summary(english:"Checks dpkg output for the updated package");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Debian host is missing a security-related update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Daniel B. Cid discovered that fail2ban, a tool to block IP addresses
that cause login failures, is too liberal about parsing SSH log files,
allowing an attacker to block any IP address."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.debian.org/security/2008/dsa-1456"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade the fail2ban package.

The old stable distribution (sarge) doesn't contain fail2ban.

For the stable distribution (etch), this problem has been fixed in
version 0.7.5-2etch1."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:fail2ban");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:4.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2008/01/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2008/01/10");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2008-2019 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:"4.0", prefix:"fail2ban", reference:"0.7.5-2etch1")) 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");