Vulnerabilities > CVE-2011-2769 - Information Exposure vulnerability in TOR
Attack vector
UNKNOWN Attack complexity
UNKNOWN Privileges required
UNKNOWN Confidentiality impact
UNKNOWN Integrity impact
UNKNOWN Availability impact
UNKNOWN Summary
Tor before 0.2.2.34, when configured as a bridge, accepts the CREATE and CREATE_FAST values in the Command field of a cell within an OR connection that it initiated, which allows remote relays to enumerate bridges by using these values.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- 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.
- Footprinting An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
- Exploiting Trust in Client (aka Make the Client Invisible) An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
- Browser Fingerprinting An attacker carefully crafts small snippets of Java Script to efficiently detect the type of browser the potential victim is using. Many web-based attacks need prior knowledge of the web browser including the version of browser to ensure successful exploitation of a vulnerability. Having this knowledge allows an attacker to target the victim with attacks that specifically exploit known or zero day weaknesses in the type and version of the browser used by the victim. Automating this process via Java Script as a part of the same delivery system used to exploit the browser is considered more efficient as the attacker can supply a browser fingerprinting method and integrate it with exploit code, all contained in Java Script and in response to the same web page request by the browser.
- Session Credential Falsification through Prediction This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.
Nessus
NASL family Debian Local Security Checks NASL id DEBIAN_DSA-2331.NASL description It has been discovered by last seen 2020-03-17 modified 2011-10-31 plugin id 56670 published 2011-10-31 reporter This script is Copyright (C) 2011-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/56670 title Debian DSA-2331-1 : tor - several vulnerabilities code #%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-2331. The text # itself is copyright (C) Software in the Public Interest, Inc. # include("compat.inc"); if (description) { script_id(56670); script_version("1.11"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/12"); script_cve_id("CVE-2011-2768", "CVE-2011-2769"); script_xref(name:"DSA", value:"2331"); script_name(english:"Debian DSA-2331-1 : tor - several vulnerabilities"); 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 has been discovered by 'frosty_un' that a design flaw in Tor, an online privacy tool, allows malicious relay servers to learn certain information that they should not be able to learn. Specifically, a relay that a user connects to directly could learn which other relays that user is connected to directly. In combination with other attacks, this issue can lead to deanonymizing the user. The Common Vulnerabilities and Exposures project has assigned CVE-2011-2768 to this issue. In addition to fixing the above mentioned issues, the updates to oldstable and stable fix a number of less critical issues (CVE-2011-2769 ). Please see the posting from the Tor blog for more information." ); script_set_attribute( attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2011-2768" ); script_set_attribute( attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2011-2769" ); # https://blog.torproject.org/blog/tor-02234-released-security-patches script_set_attribute( attribute:"see_also", value:"https://blog.torproject.org/tor-02234-released-security-patches" ); script_set_attribute( attribute:"see_also", value:"https://packages.debian.org/source/squeeze/tor" ); script_set_attribute( attribute:"see_also", value:"https://www.debian.org/security/2011/dsa-2331" ); script_set_attribute( attribute:"solution", value: "Upgrade the tor packages. For the oldstable distribution (lenny), this problem has been fixed in version 0.2.1.31-1~lenny+1. Due to technical limitations in the Debian archive scripts, the update cannot be released synchronously with the packages for stable. It will be released shortly. For the stable distribution (squeeze), this problem has been fixed in version 0.2.1.31-1." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:tor"); script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:5.0"); script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:6.0"); script_set_attribute(attribute:"patch_publication_date", value:"2011/10/28"); script_set_attribute(attribute:"plugin_publication_date", value:"2011/10/31"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2011-2020 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:"5.0", prefix:"tor", reference:"0.2.1.31-1~lenny+1")) flag++; if (deb_check(release:"6.0", prefix:"tor", reference:"0.2.1.31-1")) flag++; if (deb_check(release:"6.0", prefix:"tor-dbg", reference:"0.2.1.31-1")) flag++; if (deb_check(release:"6.0", prefix:"tor-geoipdb", reference:"0.2.1.31-1")) 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");
NASL family Fedora Local Security Checks NASL id FEDORA_2011-15117.NASL description . ---------------------------------------------------------------------- -----= Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-01 modified 2020-06-02 plugin id 56720 published 2011-11-07 reporter This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/56720 title Fedora 15 : tor-0.2.1.31-1500.fc15 (2011-15117) code #%NASL_MIN_LEVEL 80502 # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Fedora Security Advisory 2011-15117. # include("compat.inc"); if (description) { script_id(56720); script_version("1.11"); script_cvs_date("Date: 2019/08/02 13:32:34"); script_cve_id("CVE-2011-2768", "CVE-2011-2769"); script_bugtraq_id(50414); script_xref(name:"FEDORA", value:"2011-15117"); script_name(english:"Fedora 15 : tor-0.2.1.31-1500.fc15 (2011-15117)"); script_summary(english:"Checks rpm output for the updated package."); script_set_attribute( attribute:"synopsis", value:"The remote Fedora host is missing a security update." ); script_set_attribute( attribute:"description", value: ". ---------------------------------------------------------------------- -----= Note that Tenable Network Security has extracted the preceding description block directly from the Fedora 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://bugzilla.redhat.com/show_bug.cgi?id=749839" ); # https://lists.fedoraproject.org/pipermail/package-announce/2011-November/068757.html script_set_attribute( attribute:"see_also", value:"http://www.nessus.org/u?11a0e618" ); script_set_attribute(attribute:"solution", value:"Update the affected tor package."); script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/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:fedoraproject:fedora:tor"); script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:15"); script_set_attribute(attribute:"patch_publication_date", value:"2011/10/29"); script_set_attribute(attribute:"plugin_publication_date", value:"2011/11/07"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"Fedora Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list"); exit(0); } include("audit.inc"); include("global_settings.inc"); include("rpm.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); release = get_kb_item("Host/RedHat/release"); if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora"); os_ver = eregmatch(pattern: "Fedora.*release ([0-9]+)", string:release); if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora"); os_ver = os_ver[1]; if (! ereg(pattern:"^15([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 15.x", "Fedora " + os_ver); if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu); flag = 0; if (rpm_check(release:"FC15", reference:"tor-0.2.1.31-1500.fc15")) flag++; if (flag) { if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get()); else security_warning(0); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "tor"); }
NASL family Gentoo Local Security Checks NASL id GENTOO_GLSA-201201-12.NASL description The remote host is affected by the vulnerability described in GLSA-201201-12 (Tor: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Tor: When configured as client or bridge, Tor uses the same TLS certificate chain for all outgoing connections (CVE-2011-2768). When configured as a bridge, Tor relays can distinguish incoming bridge connections from client connections (CVE-2011-2769). An error in or/buffers.c could result in a heap-based buffer overflow (CVE-2011-2778). Impact : A remote attacker could possibly execute arbitrary code or cause a Denial of Service. Furthermore, a remote relay the user is directly connected to may be able to disclose anonymous information about that user or enumerate bridges in the user last seen 2020-06-01 modified 2020-06-02 plugin id 57654 published 2012-01-24 reporter This script is Copyright (C) 2012-2018 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/57654 title GLSA-201201-12 : Tor: Multiple vulnerabilities code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Gentoo Linux Security Advisory GLSA 201201-12. # # The advisory text is Copyright (C) 2001-2016 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(57654); script_version("1.7"); script_cvs_date("Date: 2018/07/11 17:09:26"); script_cve_id("CVE-2011-2768", "CVE-2011-2769", "CVE-2011-2778"); script_bugtraq_id(50414, 51097); script_xref(name:"GLSA", value:"201201-12"); script_name(english:"GLSA-201201-12 : Tor: Multiple vulnerabilities"); 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-201201-12 (Tor: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Tor: When configured as client or bridge, Tor uses the same TLS certificate chain for all outgoing connections (CVE-2011-2768). When configured as a bridge, Tor relays can distinguish incoming bridge connections from client connections (CVE-2011-2769). An error in or/buffers.c could result in a heap-based buffer overflow (CVE-2011-2778). Impact : A remote attacker could possibly execute arbitrary code or cause a Denial of Service. Furthermore, a remote relay the user is directly connected to may be able to disclose anonymous information about that user or enumerate bridges in the user's connection. Workaround : There is no known workaround at this time." ); script_set_attribute( attribute:"see_also", value:"https://security.gentoo.org/glsa/201201-12" ); script_set_attribute( attribute:"solution", value: "All Tor users should upgrade to the latest version: # emerge --sync # emerge --ask --oneshot --verbose '>=net-misc/tor-0.2.2.35'" ); script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C"); 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:gentoo:linux:tor"); script_set_attribute(attribute:"cpe", value:"cpe:/o:gentoo:linux"); script_set_attribute(attribute:"patch_publication_date", value:"2012/01/23"); script_set_attribute(attribute:"plugin_publication_date", value:"2012/01/24"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2012-2018 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-misc/tor", unaffected:make_list("ge 0.2.2.35"), vulnerable:make_list("lt 0.2.2.35"))) flag++; if (flag) { if (report_verbosity > 0) security_hole(port:0, extra:qpkg_report_get()); else security_hole(0); exit(0); } else { tested = qpkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "Tor"); }
NASL family Fedora Local Security Checks NASL id FEDORA_2011-15208.NASL description . ---------------------------------------------------------------------- -----= Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-01 modified 2020-06-02 plugin id 56796 published 2011-11-14 reporter This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/56796 title Fedora 16 : tor-0.2.2.34-1600.fc16 (2011-15208) NASL family Mandriva Local Security Checks NASL id MANDRIVA_MDVSA-2013-132.NASL description Updated tor package fixes security vulnerabilities : Tor before 0.2.2.34, when configured as a client or bridge, sends a TLS certificate chain as part of an outgoing OR connection, which allows remote relays to bypass intended anonymity properties by reading this chain and then determining the set of entry guards that the client or bridge had selected (CVE-2011-2768). Tor before 0.2.2.34, when configured as a bridge, accepts the CREATE and CREATE_FAST values in the Command field of a cell within an OR connection that it initiated, which allows remote relays to enumerate bridges by using these values (CVE-2011-2769). Use-after-free vulnerability in dns.c in Tor before 0.2.2.38 might allow remote attackers to cause a denial of service (daemon crash) via vectors related to failed DNS requests (CVE-2012-3517). The networkstatus_parse_vote_from_string function in routerparse.c in Tor before 0.2.2.38 does not properly handle an invalid flavor name, which allows remote attackers to cause a denial of service (out-of-bounds read and daemon crash) via a crafted (1) vote document or (2) consensus document (CVE-2012-3518). routerlist.c in Tor before 0.2.2.38 uses a different amount of time for relay-list iteration depending on which relay is chosen, which might allow remote attackers to obtain sensitive information about relay selection via a timing side-channel attack (CVE-2012-3519). The compare_tor_addr_to_addr_policy function in or/policies.c in Tor before 0.2.2.39, and 0.2.3.x before 0.2.3.21-rc, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a zero-valued port field that is not properly handled during policy comparison (CVE-2012-4419). Tor before 0.2.2.39, when waiting for a client to renegotiate, allowed it to add bytes to the input buffer, allowing a crash to be caused remotely (tor-5934, tor-6007). Denial of Service vulnerability in Tor before 0.2.3.25, due to an error when handling SENDME cells and can be exploited to cause excessive consumption of memory resources within an entry node (SA51329, CVE-2012-5573). The version of Tor shipped in MBS1 did not have correctly formed systemd unit and thus failed to start. This updated version corrects this problem and restores working behaviour. last seen 2020-06-01 modified 2020-06-02 plugin id 66144 published 2013-04-20 reporter This script is Copyright (C) 2013-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/66144 title Mandriva Linux Security Advisory : tor (MDVSA-2013:132)