CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:N/I:P/A:N
EPSS
Percentile
51.9%
It was discovered that PyOpenSSL, a Python wrapper around the OpenSSL library, does not properly handle certificates with NULL characters in the Subject Alternative Name field.
A remote attacker in the position to obtain a certificate for ‘www.foo.org\0.example.com’ from a CA that a SSL client trusts, could use this to spoof ‘www.foo.org’ and conduct man-in-the-middle attacks between the PyOpenSSL-using client and the SSL server.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DSA-2763. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(70105);
script_version("1.10");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/11");
script_cve_id("CVE-2013-4314");
script_bugtraq_id(62258);
script_xref(name:"DSA", value:"2763");
script_name(english:"Debian DSA-2763-1 : pyopenssl - hostname check bypassing");
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:
"It was discovered that PyOpenSSL, a Python wrapper around the OpenSSL
library, does not properly handle certificates with NULL characters in
the Subject Alternative Name field.
A remote attacker in the position to obtain a certificate for
'www.foo.org\0.example.com' from a CA that a SSL client trusts, could
use this to spoof 'www.foo.org' and conduct man-in-the-middle attacks
between the PyOpenSSL-using client and the SSL server."
);
script_set_attribute(
attribute:"see_also",
value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=722055"
);
script_set_attribute(
attribute:"see_also",
value:"https://packages.debian.org/source/squeeze/pyopenssl"
);
script_set_attribute(
attribute:"see_also",
value:"https://packages.debian.org/source/wheezy/pyopenssl"
);
script_set_attribute(
attribute:"see_also",
value:"https://www.debian.org/security/2013/dsa-2763"
);
script_set_attribute(
attribute:"solution",
value:
"Upgrade the pyopenssl packages.
For the oldstable distribution (squeeze), this problem has been fixed
in version 0.10-1+squeeze1.
For the stable distribution (wheezy), this problem has been fixed in
version 0.13-2+deb7u1."
);
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N");
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:pyopenssl");
script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:6.0");
script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:7.0");
script_set_attribute(attribute:"patch_publication_date", value:"2013/09/24");
script_set_attribute(attribute:"plugin_publication_date", value:"2013/09/25");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2013-2021 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:"6.0", prefix:"python-openssl", reference:"0.10-1+squeeze1")) flag++;
if (deb_check(release:"6.0", prefix:"python-openssl-dbg", reference:"0.10-1+squeeze1")) flag++;
if (deb_check(release:"6.0", prefix:"python-openssl-doc", reference:"0.10-1+squeeze1")) flag++;
if (deb_check(release:"7.0", prefix:"python-openssl", reference:"0.13-2+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"python-openssl-dbg", reference:"0.13-2+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"python-openssl-doc", reference:"0.13-2+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"python3-openssl", reference:"0.13-2+deb7u1")) flag++;
if (deb_check(release:"7.0", prefix:"python3-openssl-dbg", reference:"0.13-2+deb7u1")) 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");