Vulnerabilities > CVE-2019-3689 - Incorrect Default Permissions vulnerability in Linux-Nfs Nfs-Utils
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
The nfs-utils package in SUSE Linux Enterprise Server 12 before and including version 1.3.0-34.18.1 and in SUSE Linux Enterprise Server 15 before and including version 2.1.1-6.10.2 the directory /var/lib/nfs is owned by statd:nogroup. This directory contains files owned and managed by root. If statd is compromised, it can therefore trick processes running with root privileges into creating/overwriting files anywhere on the system.
Vulnerable Configurations
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.
- 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.
- 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.
- Embedding Scripts within Scripts An attack of this type exploits a programs' vulnerabilities that are brought on by allowing remote hosts to execute scripts. The attacker leverages this capability to execute scripts to execute his/her own script by embedding it within other scripts that the target software is likely to execute. The attacker must have the ability to inject script into script that is likely to be executed. If this is done, then the attacker can potentially launch a variety of probes and attacks against the web server's local environment, in many cases the so-called DMZ, back end resources the web server can communicate with, and other hosts. With the proliferation of intermediaries, such as Web App Firewalls, network devices, and even printers having JVMs and Web servers, there are many locales where an attacker can inject malicious scripts. Since this attack pattern defines scripts within scripts, there are likely privileges to execute said attack on the host. Of course, these attacks are not solely limited to the server side, client side scripts like Ajax and client side JavaScript can contain malicious scripts as well. In general all that is required is for there to be sufficient privileges to execute a script, but not protected against writing.
- Web Logs Tampering Web Logs Tampering attacks involve an attacker injecting, deleting or otherwise tampering with the contents of web logs typically for the purposes of masking other malicious behavior. Additionally, writing malicious data to log files may target jobs, filters, reports, and other agents that process the logs in an asynchronous attack pattern. This pattern of attack is similar to "Log Injection-Tampering-Forging" except that in this case, the attack is targeting the logs of the web server and not the application.
Nessus
NASL family SuSE Local Security Checks NASL id OPENSUSE-2019-2435.NASL description This update for nfs-utils fixes the following issues : - CVE-2019-3689: Fixed root-owned files stored in insecure /var/lib/nfs. (bsc#1150733) This update was imported from the SUSE:SLE-15-SP1:Update update project. last seen 2020-06-01 modified 2020-06-02 plugin id 130578 published 2019-11-06 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/130578 title openSUSE Security Update : nfs-utils (openSUSE-2019-2435) code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from openSUSE Security Update openSUSE-2019-2435. # # The text description of this plugin is (C) SUSE LLC. # include("compat.inc"); if (description) { script_id(130578); script_version("1.3"); script_cvs_date("Date: 2019/12/17"); script_cve_id("CVE-2019-3689"); script_name(english:"openSUSE Security Update : nfs-utils (openSUSE-2019-2435)"); script_summary(english:"Check for the openSUSE-2019-2435 patch"); script_set_attribute( attribute:"synopsis", value:"The remote openSUSE host is missing a security update." ); script_set_attribute( attribute:"description", value: "This update for nfs-utils fixes the following issues : - CVE-2019-3689: Fixed root-owned files stored in insecure /var/lib/nfs. (bsc#1150733) This update was imported from the SUSE:SLE-15-SP1:Update update project." ); script_set_attribute( attribute:"see_also", value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1150733" ); script_set_attribute( attribute:"solution", value:"Update the affected nfs-utils packages." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C"); script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C"); 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_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:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:nfs-client"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:nfs-client-debuginfo"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:nfs-kernel-server"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:nfs-kernel-server-debuginfo"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:nfs-utils-debuginfo"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:nfs-utils-debugsource"); script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.1"); script_set_attribute(attribute:"vuln_publication_date", value:"2019/09/19"); script_set_attribute(attribute:"patch_publication_date", value:"2019/11/05"); script_set_attribute(attribute:"plugin_publication_date", value:"2019/11/06"); script_set_attribute(attribute:"generated_plugin", value:"current"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"SuSE Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/SuSE/release", "Host/SuSE/rpm-list", "Host/cpu"); 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/SuSE/release"); if (isnull(release) || release =~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "openSUSE"); if (release !~ "^(SUSE15\.1)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.1", release); if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); ourarch = get_kb_item("Host/cpu"); if (!ourarch) audit(AUDIT_UNKNOWN_ARCH); if (ourarch !~ "^(i586|i686|x86_64)$") audit(AUDIT_ARCH_NOT, "i586 / i686 / x86_64", ourarch); flag = 0; if ( rpm_check(release:"SUSE15.1", reference:"nfs-client-2.1.1-lp151.7.3.1") ) flag++; if ( rpm_check(release:"SUSE15.1", reference:"nfs-client-debuginfo-2.1.1-lp151.7.3.1") ) flag++; if ( rpm_check(release:"SUSE15.1", reference:"nfs-kernel-server-2.1.1-lp151.7.3.1") ) flag++; if ( rpm_check(release:"SUSE15.1", reference:"nfs-kernel-server-debuginfo-2.1.1-lp151.7.3.1") ) flag++; if ( rpm_check(release:"SUSE15.1", reference:"nfs-utils-debuginfo-2.1.1-lp151.7.3.1") ) flag++; if ( rpm_check(release:"SUSE15.1", reference:"nfs-utils-debugsource-2.1.1-lp151.7.3.1") ) flag++; if (flag) { if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get()); else security_hole(0); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "nfs-client / nfs-client-debuginfo / nfs-kernel-server / etc"); }
NASL family SuSE Local Security Checks NASL id SUSE_SU-2019-2782-1.NASL description This update for nfs-utils fixes the following issues : CVE-2019-3689: Fixed root-owned files stored in insecure /var/lib/nfs. (bsc#1150733) Note that Tenable Network Security has extracted the preceding description block directly from the SUSE 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 130342 published 2019-10-28 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/130342 title SUSE SLED15 / SLES15 Security Update : nfs-utils (SUSE-SU-2019:2782-1) NASL family SuSE Local Security Checks NASL id SUSE_SU-2019-2781-1.NASL description This update for nfs-utils fixes the following issues : CVE-2019-3689: Fixed root-owned files stored in insecure /var/lib/nfs. (bsc#1150733) Note that Tenable Network Security has extracted the preceding description block directly from the SUSE 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 130341 published 2019-10-28 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/130341 title SUSE SLED12 / SLES12 Security Update : nfs-utils (SUSE-SU-2019:2781-1) NASL family Debian Local Security Checks NASL id DEBIAN_DLA-1965.NASL description In the nfs-utils package, providing support files for Network File System (NFS) including the rpc.statd daemon, the directory /var/lib/nfs is owned by statd:nogroup. This directory contains files owned and managed by root. If statd is compromised, it can therefore trick processes running with root privileges into creating/overwriting files anywhere on the system. For Debian 8 last seen 2020-06-01 modified 2020-06-02 plugin id 130071 published 2019-10-21 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/130071 title Debian DLA-1965-1 : nfs-utils security update NASL family SuSE Local Security Checks NASL id SUSE_SU-2019-2776-1.NASL description This update for nfs-utils fixes the following issues : CVE-2019-3689: Fixed root-owned files stored in insecure /var/lib/nfs. (bsc#1150733) Note that Tenable Network Security has extracted the preceding description block directly from the SUSE 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 130255 published 2019-10-25 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/130255 title SUSE SLED15 / SLES15 Security Update : nfs-utils (SUSE-SU-2019:2776-1) NASL family SuSE Local Security Checks NASL id OPENSUSE-2019-2408.NASL description This update for nfs-utils fixes the following issues : - CVE-2019-3689: Fixed root-owned files stored in insecure /var/lib/nfs. (bsc#1150733) This update was imported from the SUSE:SLE-15:Update update project. last seen 2020-06-01 modified 2020-06-02 plugin id 130387 published 2019-10-30 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/130387 title openSUSE Security Update : nfs-utils (openSUSE-2019-2408) NASL family SuSE Local Security Checks NASL id SUSE_SU-2019-2771-1.NASL description This update for nfs-utils fixes the following issues : CVE-2019-3689: Fixed root-owned files stored in insecure /var/lib/nfs. (bsc#1150733) Note that Tenable Network Security has extracted the preceding description block directly from the SUSE 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 130254 published 2019-10-25 reporter This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/130254 title SUSE SLES12 Security Update : nfs-utils (SUSE-SU-2019:2771-1)
References
- https://bugzilla.suse.com/show_bug.cgi?id=1150733
- https://lists.debian.org/debian-lts-announce/2019/10/msg00026.html
- http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00071.html
- http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00006.html
- https://usn.ubuntu.com/4400-1/
- https://git.linux-nfs.org/?p=steved/nfs-utils.git%3Ba=commitdiff%3Bh=fee2cc29e888f2ced6a76990923aef19d326dc0e