Vulnerabilities > CVE-2016-7143 - Improper Authorization vulnerability in multiple products

047910
CVSS 6.8 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL

Summary

The m_authenticate function in modules/m_sasl.c in Charybdis before 3.5.3 allows remote attackers to spoof certificate fingerprints and consequently log in as another user via a crafted AUTHENTICATE parameter.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Accessing Functionality Not Properly Constrained by ACLs
    In applications, particularly web applications, access to functionality is mitigated by the authorization framework, whose job it is to map ACLs to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application or can run queries for data that he is otherwise not supposed to.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Directory Indexing
    An adversary crafts a request to a target that results in the target listing/indexing the content of a directory as output. One common method of triggering directory contents as output is to construct a request containing a path that terminates in a directory name rather than a file name since many applications are configured to provide a list of the directory's contents when such a request is received. An adversary can use this to explore the directory tree on a target as well as learn the names of files. This can often end up revealing test files, backup files, temporary files, hidden files, configuration files, user accounts, script contents, as well as naming conventions, all of which can be used by an attacker to mount additional attacks.
  • Subverting Environment Variable Values
    The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.

Nessus

NASL familyDebian Local Security Checks
NASL idDEBIAN_DSA-3661.NASL
descriptionIt was discovered that incorrect SASL authentication in the Charybdis IRC server may lead to users impersonating other users.
last seen2020-06-01
modified2020-06-02
plugin id93354
published2016-09-08
reporterThis script is Copyright (C) 2016-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/93354
titleDebian DSA-3661-1 : charybdis - security update
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Debian Security Advisory DSA-3661. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(93354);
  script_version("2.8");
  script_cvs_date("Date: 2018/11/10 11:49:38");

  script_cve_id("CVE-2016-7143");
  script_xref(name:"DSA", value:"3661");

  script_name(english:"Debian DSA-3661-1 : charybdis - security update");
  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 incorrect SASL authentication in the Charybdis
IRC server may lead to users impersonating other users."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/jessie/charybdis"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.debian.org/security/2016/dsa-3661"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade the charybdis packages.

For the stable distribution (jessie), this problem has been fixed in
version 3.4.2-5+deb8u2."
  );
  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_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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:"exploit_available", value:"false");

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

  script_set_attribute(attribute:"patch_publication_date", value:"2016/09/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/09/08");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2018 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:"charybdis", reference:"3.4.2-5+deb8u2")) flag++;
if (deb_check(release:"8.0", prefix:"charybdis-dbg", reference:"3.4.2-5+deb8u2")) 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");