Vulnerabilities > CVE-2018-1000550 - Path Traversal vulnerability in multiple products

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
sympa
debian
CWE-22
nessus
NVD
Published: 2018-06-26
Updated: 2020-08-04

Summary

The Sympa Community Sympa version prior to version 6.2.32 contains a Directory Traversal vulnerability in wwsympa.fcgi template editing function that can result in Possibility to create or modify files on the server filesystem. This attack appear to be exploitable via HTTP GET/POST request. This vulnerability appears to have been fixed in 6.2.32.

Vulnerable Configurations

Part Description Count
Application
Sympa
195
OS
Debian
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Relative Path Traversal
    An attacker exploits a weakness in input validation on the target by supplying a specially constructed path utilizing dot and slash characters for the purpose of obtaining access to arbitrary files or resources. An attacker modifies a known path on the target in order to reach material that is not available through intended channels. These attacks normally involve adding additional path separators (/ or \) and/or dots (.), or encodings thereof, in various combinations in order to reach parent directories or entirely separate trees of the target's directory structure.
  • Directory Traversal
    An attacker with access to file system resources, either directly or via application logic, will use various file path specification or navigation mechanisms such as ".." in path strings and absolute paths to extend their range of access to inappropriate areas of the file system. The attacker attempts to either explore the file system for recon purposes or access directories and files that are intended to be restricted from their access. Exploring the file system can be achieved through constructing paths presented to directory listing programs, such as "ls" and 'dir', or through specially crafted programs that attempt to explore the file system. The attacker engaging in this type of activity is searching for information that can be used later in a more exploitive attack. Access to restricted directories or files can be achieved through modification of path references utilized by system applications.
  • File System Function Injection, Content Based
    An attack of this type exploits the host's trust in executing remote content including binary files. The files are poisoned with a malicious payload (targeting the file systems accessible by the target software) by the attacker and may be passed through standard channels such as via email, and standard web content like PDF and multimedia files. The attacker exploits known vulnerabilities or handling routines in the target processes. Vulnerabilities of this type have been found in a wide variety of commercial applications from Microsoft Office to Adobe Acrobat and Apple Safari web browser. When the attacker knows the standard handling routines and can identify vulnerabilities and entry points they can be exploited by otherwise seemingly normal content. Once the attack is executed, the attackers' program can access relative directories such as C:\Program Files or other standard system directories to launch further attacks. In a worst case scenario, these programs are combined with other propagation logic and work as a virus.
  • Using Slashes and URL Encoding Combined to Bypass Validation Logic
    This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL. An URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.

Nessus

  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-1441.NASL
    descriptionA vulnerability has been discovered in Sympa, a modern mailing list manager, that allows write access to files on the server filesystem. This flaw allows to create or modify any file writable by the Sympa user, located on the server filesystem, using the function of Sympa web interface template file saving. For Debian 8
    last seen2020-06-01
    modified2020-06-02
    plugin id111313
    published2018-07-25
    reporterThis script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/111313
    titleDebian DLA-1441-1 : sympa security update
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-1441-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(111313);
  script_version("1.3");
  script_cvs_date("Date: 2018/08/31 12:25:01");

  script_cve_id("CVE-2018-1000550");

  script_name(english:"Debian DLA-1441-1 : sympa 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 update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"A vulnerability has been discovered in Sympa, a modern mailing list
manager, that allows write access to files on the server filesystem.
This flaw allows to create or modify any file writable by the Sympa
user, located on the server filesystem, using the function of Sympa
web interface template file saving.

For Debian 8 'Jessie', this problem has been fixed in version
6.1.23~dfsg-2+deb8u2.

We recommend that you upgrade your sympa 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/2018/07/msg00033.html"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/jessie/sympa"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Upgrade the affected sympa package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");

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

  script_set_attribute(attribute:"patch_publication_date", value:"2018/07/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/07/25");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 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:"sympa", reference:"6.1.23~dfsg-2+deb8u2")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get());
  else security_hole(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4285.NASL
    descriptionMichael Kaczmarczik discovered a vulnerability in the web interface template editing function of Sympa, a mailing list manager. Owner and listmasters could use this flaw to create or modify arbitrary files in the server with privileges of sympa user or owner view list config files even if edit_list.conf prohibits it.
    last seen2020-06-01
    modified2020-06-02
    plugin id117297
    published2018-09-06
    reporterThis script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/117297
    titleDebian DSA-4285-1 : sympa - security update
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Debian Security Advisory DSA-4285. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(117297);
  script_version("1.3");
  script_cvs_date("Date: 2018/11/13 12:30:47");

  script_cve_id("CVE-2018-1000550");
  script_xref(name:"DSA", value:"4285");

  script_name(english:"Debian DSA-4285-1 : sympa - 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:
"Michael Kaczmarczik discovered a vulnerability in the web interface
template editing function of Sympa, a mailing list manager. Owner and
listmasters could use this flaw to create or modify arbitrary files in
the server with privileges of sympa user or owner view list config
files even if edit_list.conf prohibits it."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://security-tracker.debian.org/tracker/source-package/sympa"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/stretch/sympa"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.debian.org/security/2018/dsa-4285"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade the sympa packages.

For the stable distribution (stretch), this problem has been fixed in
version 6.2.16~dfsg-3+deb9u1."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:sympa");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/09/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/09/06");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 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:"9.0", prefix:"sympa", reference:"6.2.16~dfsg-3+deb9u1")) flag++;

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

References