Vulnerabilities > CVE-2016-9818 - Improper Access Control vulnerability in XEN 4.7.0/4.7.1
Attack vector
LOCAL Attack complexity
LOW Privileges required
LOW Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
Xen through 4.7.x allows local ARM guest OS users to cause a denial of service (host crash) via vectors involving an asynchronous abort while at HYP.
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- 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.
- Signature Spoofing by Key Theft An attacker obtains an authoritative or reputable signer's private signature key by theft and then uses this key to forge signatures from the original signer to mislead a victim into performing actions that benefit the attacker.
Nessus
NASL family Fedora Local Security Checks NASL id FEDORA_2016-CC2916DCF4.NASL description ARM guests may induce host asynchronous abort [XSA-201, CVE-2016-9815, CVE-2016-9816, CVE-2016-9817, CVE-2016-9818] (#1399747) qemu: Divide by zero vulnerability in cirrus_do_copy (#1399055) [CVE-2016-9921, CVE-2016-9922] Qemu: 9pfs: memory leakage via proxy/handle callbacks (#1402278) qemu ioport array overflow [XSA-199, CVE-2016-9637] Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-05 modified 2016-12-20 plugin id 96025 published 2016-12-20 reporter This script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/96025 title Fedora 23 : xen (2016-cc2916dcf4) 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 FEDORA-2016-cc2916dcf4. # include("compat.inc"); if (description) { script_id(96025); script_version("3.7"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04"); script_cve_id("CVE-2016-9637", "CVE-2016-9815", "CVE-2016-9816", "CVE-2016-9817", "CVE-2016-9818", "CVE-2016-9913", "CVE-2016-9921", "CVE-2016-9922"); script_xref(name:"FEDORA", value:"2016-cc2916dcf4"); script_name(english:"Fedora 23 : xen (2016-cc2916dcf4)"); 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: "ARM guests may induce host asynchronous abort [XSA-201, CVE-2016-9815, CVE-2016-9816, CVE-2016-9817, CVE-2016-9818] (#1399747) qemu: Divide by zero vulnerability in cirrus_do_copy (#1399055) [CVE-2016-9921, CVE-2016-9922] Qemu: 9pfs: memory leakage via proxy/handle callbacks (#1402278) qemu ioport array overflow [XSA-199, CVE-2016-9637] Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. 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://bodhi.fedoraproject.org/updates/FEDORA-2016-cc2916dcf4" ); script_set_attribute(attribute:"solution", value:"Update the affected xen package."); script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:xen"); script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:23"); script_set_attribute(attribute:"vuln_publication_date", value:"2016/12/23"); script_set_attribute(attribute:"patch_publication_date", value:"2016/12/18"); script_set_attribute(attribute:"plugin_publication_date", value:"2016/12/20"); script_set_attribute(attribute:"generated_plugin", value:"current"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2016-2020 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 = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release); if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora"); os_ver = os_ver[1]; if (! preg(pattern:"^23([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 23", "Fedora " + os_ver); if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING); cpu = get_kb_item("Host/cpu"); if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH); if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu); flag = 0; if (rpm_check(release:"FC23", reference:"xen-4.5.5-5.fc23")) flag++; if (flag) { security_report_v4( port : 0, severity : SECURITY_WARNING, extra : rpm_report_get() ); exit(0); } else { tested = pkg_tests_get(); if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested); else audit(AUDIT_PACKAGE_NOT_INSTALLED, "xen"); }
NASL family Gentoo Local Security Checks NASL id GENTOO_GLSA-201612-56.NASL description The remote host is affected by the vulnerability described in GLSA-201612-56 (Xen: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Xen. Please review the CVE identifiers referenced below for details. Impact : A local attacker could possibly execute arbitrary code with the privileges of the process, could gain privileges on the host system, cause a Denial of Service condition, or obtain sensitive information. Workaround : There is no known workaround at this time. last seen 2020-06-01 modified 2020-06-02 plugin id 96231 published 2017-01-03 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/96231 title GLSA-201612-56 : Xen: Multiple vulnerabilities NASL family Fedora Local Security Checks NASL id FEDORA_2016-BCBAE0781F.NASL description x86 CMPXCHG8B emulation fails to ignore operand size override [XSA-200, CVE-2016-9932] (#1404262) ---- ARM guests may induce host asynchronous abort [XSA-201, CVE-2016-9815, CVE-2016-9816, CVE-2016-9817, CVE-2016-9818] (#1399747) qemu: Divide by zero vulnerability in cirrus_do_copy (#1399055) [CVE-2016-9921, CVE-2016-9922] Qemu: 9pfs: memory leakage via proxy/handle callbacks (#1402278) qemu ioport array overflow [XSA-199, CVE-2016-9637] Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues. last seen 2020-06-05 modified 2016-12-27 plugin id 96113 published 2016-12-27 reporter This script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/96113 title Fedora 24 : xen (2016-bcbae0781f)
References
- http://xenbits.xen.org/xsa/xsa201-4.patch
- http://xenbits.xen.org/xsa/advisory-201.html
- http://www.securityfocus.com/bid/94581
- http://www.openwall.com/lists/oss-security/2016/12/05/7
- http://www.openwall.com/lists/oss-security/2016/11/29/3
- https://security.gentoo.org/glsa/201612-56
- http://www.securitytracker.com/id/1037358