Vulnerabilities > CVE-2015-7975 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in NTP

047910
CVSS 6.2 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
local
low complexity
ntp
CWE-119
nessus

Summary

The nextvar function in NTP before 4.2.8p6 and 4.3.x before 4.3.90 does not properly validate the length of its input, which allows an attacker to cause a denial of service (application crash).

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Overflow Buffers
    Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
  • Client-side Injection-induced Buffer Overflow
    This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
  • Filter Failure through Buffer Overflow
    In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
  • MIME Conversion
    An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.

Nessus

  • NASL familySlackware Local Security Checks
    NASL idSLACKWARE_SSA_2016-054-04.NASL
    descriptionNew ntp packages are available for Slackware 13.0, 13.1, 13.37, 14.0, 14.1, and -current to fix security issues.
    last seen2020-06-01
    modified2020-06-02
    plugin id88912
    published2016-02-24
    reporterThis script is Copyright (C) 2016-2017 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/88912
    titleSlackware 13.0 / 13.1 / 13.37 / 14.0 / 14.1 / current : ntp (SSA:2016-054-04)
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_5237F5D7C02011E5B397D050996490D0.NASL
    descriptionNetwork Time Foundation reports : NTF
    last seen2020-06-01
    modified2020-06-02
    plugin id88068
    published2016-01-22
    reporterThis script is Copyright (C) 2016-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/88068
    titleFreeBSD : ntp -- multiple vulnerabilities (5237f5d7-c020-11e5-b397-d050996490d0)
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2016-649.NASL
    descriptionThis update for ntp fixes the following issues : - Update to 4.2.8p7 (boo#977446) : - CVE-2016-1547, boo#977459: Validate crypto-NAKs, AKA: CRYPTO-NAK DoS. - CVE-2016-1548, boo#977461: Interleave-pivot - CVE-2016-1549, boo#977451: Sybil vulnerability: ephemeral association attack. - CVE-2016-1550, boo#977464: Improve NTP security against buffer comparison timing attacks. - CVE-2016-1551, boo#977450: Refclock impersonation vulnerability - CVE-2016-2516, boo#977452: Duplicate IPs on unconfig directives will cause an assertion botch in ntpd. - CVE-2016-2517, boo#977455: remote configuration trustedkey/ requestkey/controlkey values are not properly validated. - CVE-2016-2518, boo#977457: Crafted addpeer with hmode > 7 causes array wraparound with MATCH_ASSOC. - CVE-2016-2519, boo#977458: ctl_getitem() return value not always checked. - integrate ntp-fork.patch - Improve the fixes for: CVE-2015-7704, CVE-2015-7705, CVE-2015-7974 - Restrict the parser in the startup script to the first occurrance of
    last seen2020-06-05
    modified2016-06-01
    plugin id91403
    published2016-06-01
    reporterThis script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/91403
    titleopenSUSE Security Update : ntp (openSUSE-2016-649)
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2016-1247-1.NASL
    descriptionntp was updated to version 4.2.8p6 to fix 28 security issues. Major functional changes : - The
    last seen2020-06-01
    modified2020-06-02
    plugin id90991
    published2016-05-09
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/90991
    titleSUSE SLED12 / SLES12 Security Update : ntp (SUSE-SU-2016:1247-1)
  • NASL familyFirewalls
    NASL idPFSENSE_SA-16_02.NASL
    descriptionAccording to its self-reported version number, the remote pfSense install is prior to 2.3. It is, therefore, affected by multiple vulnerabilities.
    last seen2020-06-01
    modified2020-06-02
    plugin id106499
    published2018-01-31
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/106499
    titlepfSense < 2.3 Multiple Vulnerabilities (SA-16_01 - SA-16_02)
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2016-1175-1.NASL
    descriptionntp was updated to version 4.2.8p6 to fix 12 security issues. These security issues were fixed : - CVE-2015-8158: Fixed potential infinite loop in ntpq (bsc#962966). - CVE-2015-8138: Zero Origin Timestamp Bypass (bsc#963002). - CVE-2015-7979: Off-path Denial of Service (DoS) attack on authenticated broadcast mode (bsc#962784). - CVE-2015-7978: Stack exhaustion in recursive traversal of restriction list (bsc#963000). - CVE-2015-7977: reslist NULL pointer dereference (bsc#962970). - CVE-2015-7976: ntpq saveconfig command allows dangerous characters in filenames (bsc#962802). - CVE-2015-7975: nextvar() missing length check (bsc#962988). - CVE-2015-7974: Skeleton Key: Missing key check allows impersonation between authenticated peers (bsc#962960). - CVE-2015-7973: Replay attack on authenticated broadcast mode (bsc#962995). - CVE-2015-8140: ntpq vulnerable to replay attacks (bsc#962994). - CVE-2015-8139: Origin Leak: ntpq and ntpdc, disclose origin (bsc#962997). - CVE-2015-5300: MITM attacker could have forced ntpd to make a step larger than the panic threshold (bsc#951629). The update package also includes non-security fixes. See advisory for details. 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 seen2020-06-01
    modified2020-06-02
    plugin id90820
    published2016-05-02
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/90820
    titleSUSE SLES11 Security Update : ntp (SUSE-SU-2016:1175-1)
  • NASL familyGentoo Local Security Checks
    NASL idGENTOO_GLSA-201607-15.NASL
    descriptionThe remote host is affected by the vulnerability described in GLSA-201607-15 (NTP: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in NTP. Please review the CVE identifiers referenced below for details. Impact : A remote attacker could possibly cause a Denial of Service condition. Workaround : There is no known workaround at this time.
    last seen2020-06-01
    modified2020-06-02
    plugin id92485
    published2016-07-21
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/92485
    titleGLSA-201607-15 : NTP: Multiple vulnerabilities
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2016-1311-1.NASL
    descriptionThis network time protocol server ntp was updated to 4.2.8p6 to fix the following issues : Also yast2-ntp-client was updated to match some sntp syntax changes. (bsc#937837) Major functional changes : - The
    last seen2020-06-01
    modified2020-06-02
    plugin id91248
    published2016-05-19
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/91248
    titleSUSE SLES11 Security Update : ntp (SUSE-SU-2016:1311-1)
  • NASL familyMisc.
    NASL idNTP_4_2_8P6.NASL
    descriptionThe version of the remote NTP server is 3.x or 4.x prior to 4.2.8p6. It is, therefore, affected by the following vulnerabilities : - A flaw exists in the receive() function due to the use of authenticated broadcast mode. A man-in-the-middle attacker can exploit this to conduct a replay attack. (CVE-2015-7973) - A time serving flaw exists in the trusted key system due to improper key checks. An authenticated, remote attacker can exploit this to perform impersonation attacks between authenticated peers. (CVE-2015-7974) - An overflow condition exists in the nextvar() function due to improper validation of user-supplied input. A local attacker can exploit this to cause a buffer overflow, resulting in a denial of service condition. (CVE-2015-7975) - A flaw exists in ntp_control.c due to improper filtering of special characters in filenames by the saveconfig command. An authenticated, remote attacker can exploit this to inject arbitrary content. (CVE-2015-7976) - A NULL pointer dereference flaw exists in ntp_request.c that is triggered when handling ntpdc relist commands. A remote attacker can exploit this, via a specially crafted request, to crash the service, resulting in a denial of service condition. (CVE-2015-7977) - A flaw exists in ntpdc that is triggered during the handling of the relist command. A remote attacker can exploit this, via recursive traversals of the restriction list, to exhaust available space on the call stack, resulting in a denial of service condition. CVE-2015-7978) - An unspecified flaw exists in authenticated broadcast mode. A remote attacker can exploit this, via specially crafted packets, to cause a denial of service condition. (CVE-2015-7979) - A flaw exists in the receive() function that allows packets with an origin timestamp of zero to bypass security checks. A remote attacker can exploit this to spoof arbitrary content. (CVE-2015-8138) - A flaw exists in ntpq and ntpdc that allows a remote attacker to disclose sensitive information in timestamps. (CVE-2015-8139) - A flaw exists in the ntpq protocol that is triggered during the handling of an improper sequence of numbers. A man-in-the-middle attacker can exploit this to conduct a replay attack. (CVE-2015-8140) - A flaw exists in the ntpq client that is triggered when handling packets that cause a loop in the getresponse() function. A remote attacker can exploit this to cause an infinite loop, resulting in a denial of service condition. (CVE-2015-8158)
    last seen2020-06-01
    modified2020-06-02
    plugin id88054
    published2016-01-21
    reporterThis script is Copyright (C) 2016-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/88054
    titleNetwork Time Protocol Daemon (ntpd) 3.x / 4.x < 4.2.8p6 Multiple Vulnerabilities
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2016-1912-1.NASL
    descriptionNTP was updated to version 4.2.8p8 to fix several security issues and to ensure the continued maintainability of the package. These security issues were fixed : CVE-2016-4953: Bad authentication demobilized ephemeral associations (bsc#982065). CVE-2016-4954: Processing spoofed server packets (bsc#982066). CVE-2016-4955: Autokey association reset (bsc#982067). CVE-2016-4956: Broadcast interleave (bsc#982068). CVE-2016-4957: CRYPTO_NAK crash (bsc#982064). CVE-2016-1547: Validate crypto-NAKs to prevent ACRYPTO-NAK DoS (bsc#977459). CVE-2016-1548: Prevent the change of time of an ntpd client or denying service to an ntpd client by forcing it to change from basic client/server mode to interleaved symmetric mode (bsc#977461). CVE-2016-1549: Sybil vulnerability: ephemeral association attack (bsc#977451). CVE-2016-1550: Improve security against buffer comparison timing attacks (bsc#977464). CVE-2016-1551: Refclock impersonation vulnerability (bsc#977450)y CVE-2016-2516: Duplicate IPs on unconfig directives could have caused an assertion botch in ntpd (bsc#977452). CVE-2016-2517: Remote configuration trustedkey/ requestkey/controlkey values are not properly validated (bsc#977455). CVE-2016-2518: Crafted addpeer with hmode > 7 causes array wraparound with MATCH_ASSOC (bsc#977457). CVE-2016-2519: ctl_getitem() return value not always checked (bsc#977458). CVE-2015-8158: Potential Infinite Loop in ntpq (bsc#962966). CVE-2015-8138: Zero Origin Timestamp Bypass (bsc#963002). CVE-2015-7979: Off-path Denial of Service (DoS) attack on authenticated broadcast mode (bsc#962784). CVE-2015-7978: Stack exhaustion in recursive traversal of restriction list (bsc#963000). CVE-2015-7977: reslist NULL pointer dereference (bsc#962970). CVE-2015-7976: ntpq saveconfig command allowed dangerous characters in filenames (bsc#962802). CVE-2015-7975: nextvar() missing length check (bsc#962988). CVE-2015-7974: NTP did not verify peer associations of symmetric keys when authenticating packets, which might have allowed remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a
    last seen2020-06-01
    modified2020-06-02
    plugin id93186
    published2016-08-29
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/93186
    titleSUSE SLES10 Security Update : ntp (SUSE-SU-2016:1912-1)
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2016-1177-1.NASL
    descriptionntp was updated to version 4.2.8p6 to fix 12 security issues. Also yast2-ntp-client was updated to match some sntp syntax changes. (bsc#937837) These security issues were fixed : - CVE-2015-8158: Fixed potential infinite loop in ntpq (bsc#962966). - CVE-2015-8138: Zero Origin Timestamp Bypass (bsc#963002). - CVE-2015-7979: Off-path Denial of Service (DoS) attack on authenticated broadcast mode (bsc#962784). - CVE-2015-7978: Stack exhaustion in recursive traversal of restriction list (bsc#963000). - CVE-2015-7977: reslist NULL pointer dereference (bsc#962970). - CVE-2015-7976: ntpq saveconfig command allows dangerous characters in filenames (bsc#962802). - CVE-2015-7975: nextvar() missing length check (bsc#962988). - CVE-2015-7974: Skeleton Key: Missing key check allows impersonation between authenticated peers (bsc#962960). - CVE-2015-7973: Replay attack on authenticated broadcast mode (bsc#962995). - CVE-2015-8140: ntpq vulnerable to replay attacks (bsc#962994). - CVE-2015-8139: Origin Leak: ntpq and ntpdc, disclose origin (bsc#962997). - CVE-2015-5300: MITM attacker could have forced ntpd to make a step larger than the panic threshold (bsc#951629). The update package also includes non-security fixes. See advisory for details. 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 seen2020-06-01
    modified2020-06-02
    plugin id90821
    published2016-05-02
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/90821
    titleSUSE SLED12 / SLES12 Security Update : ntp (SUSE-SU-2016:1177-1)
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-3096-1.NASL
    descriptionAanchal Malhotra discovered that NTP incorrectly handled authenticated broadcast mode. A remote attacker could use this issue to perform a replay attack. (CVE-2015-7973) Matt Street discovered that NTP incorrectly verified peer associations of symmetric keys. A remote attacker could use this issue to perform an impersonation attack. (CVE-2015-7974) Jonathan Gardner discovered that the NTP ntpq utility incorrectly handled memory. An attacker could possibly use this issue to cause ntpq to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS. (CVE-2015-7975) Jonathan Gardner discovered that the NTP ntpq utility incorrectly handled dangerous characters in filenames. An attacker could possibly use this issue to overwrite arbitrary files. (CVE-2015-7976) Stephen Gray discovered that NTP incorrectly handled large restrict lists. An attacker could use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2015-7977, CVE-2015-7978) Aanchal Malhotra discovered that NTP incorrectly handled authenticated broadcast mode. A remote attacker could use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2015-7979) Jonathan Gardner discovered that NTP incorrectly handled origin timestamp checks. A remote attacker could use this issue to spoof peer servers. (CVE-2015-8138) Jonathan Gardner discovered that the NTP ntpq utility did not properly handle certain incorrect values. An attacker could possibly use this issue to cause ntpq to hang, resulting in a denial of service. (CVE-2015-8158) It was discovered that the NTP cronjob incorrectly cleaned up the statistics directory. A local attacker could possibly use this to escalate privileges. (CVE-2016-0727) Stephen Gray and Matthew Van Gundy discovered that NTP incorrectly validated crypto-NAKs. A remote attacker could possibly use this issue to prevent clients from synchronizing. (CVE-2016-1547) Miroslav Lichvar and Jonathan Gardner discovered that NTP incorrectly handled switching to interleaved symmetric mode. A remote attacker could possibly use this issue to prevent clients from synchronizing. (CVE-2016-1548) Matthew Van Gundy, Stephen Gray and Loganaden Velvindron discovered that NTP incorrectly handled message authentication. A remote attacker could possibly use this issue to recover the message digest key. (CVE-2016-1550) Yihan Lian discovered that NTP incorrectly handled duplicate IPs on unconfig directives. An authenticated remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2016-2516) Yihan Lian discovered that NTP incorrectly handled certail peer associations. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2016-2518) Jakub Prokes discovered that NTP incorrectly handled certain spoofed packets. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-4954) Miroslav Lichvar discovered that NTP incorrectly handled certain packets when autokey is enabled. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-4955) Miroslav Lichvar discovered that NTP incorrectly handled certain spoofed broadcast packets. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-4956) In the default installation, attackers would be isolated by the NTP AppArmor profile. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-06-01
    modified2020-06-02
    plugin id93896
    published2016-10-06
    reporterUbuntu Security Notice (C) 2016-2019 Canonical, Inc. / NASL script (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/93896
    titleUbuntu 12.04 LTS / 14.04 LTS / 16.04 LTS : ntp vulnerabilities (USN-3096-1)
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2016-578.NASL
    descriptionntp was updated to version 4.2.8p6 to fix 12 security issues. Also yast2-ntp-client was updated to match some sntp syntax changes. (bsc#937837) These security issues were fixed : - CVE-2015-8158: Fixed potential infinite loop in ntpq (bsc#962966). - CVE-2015-8138: Zero Origin Timestamp Bypass (bsc#963002). - CVE-2015-7979: Off-path Denial of Service (DoS) attack on authenticated broadcast mode (bsc#962784). - CVE-2015-7978: Stack exhaustion in recursive traversal of restriction list (bsc#963000). - CVE-2015-7977: reslist NULL pointer dereference (bsc#962970). - CVE-2015-7976: ntpq saveconfig command allows dangerous characters in filenames (bsc#962802). - CVE-2015-7975: nextvar() missing length check (bsc#962988). - CVE-2015-7974: Skeleton Key: Missing key check allows impersonation between authenticated peers (bsc#962960). - CVE-2015-7973: Replay attack on authenticated broadcast mode (bsc#962995). - CVE-2015-8140: ntpq vulnerable to replay attacks (bsc#962994). - CVE-2015-8139: Origin Leak: ntpq and ntpdc, disclose origin (bsc#962997). - CVE-2015-5300: MITM attacker could have forced ntpd to make a step larger than the panic threshold (bsc#951629). These non-security issues were fixed : - fate#320758 bsc#975981: Enable compile-time support for MS-SNTP (--enable-ntp-signd). This replaces the w32 patches in 4.2.4 that added the authreg directive. - bsc#962318: Call /usr/sbin/sntp with full path to synchronize in start-ntpd. When run as cron job, /usr/sbin/ is not in the path, which caused the synchronization to fail. - bsc#782060: Speedup ntpq. - bsc#916617: Add /var/db/ntp-kod. - bsc#956773: Add ntp-ENOBUFS.patch to limit a warning that might happen quite a lot on loaded systems. - bsc#951559,bsc#975496: Fix the TZ offset output of sntp during DST. - Add ntp-fork.patch and build with threads disabled to allow name resolution even when running chrooted. This update was imported from the SUSE:SLE-12-SP1:Update update project.
    last seen2020-06-05
    modified2016-05-13
    plugin id91111
    published2016-05-13
    reporterThis script is Copyright (C) 2016-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/91111
    titleopenSUSE Security Update : ntp (openSUSE-2016-578)

Talos

idTALOS-2016-0072
last seen2019-05-29
published2016-01-19
reporterTalos Intelligence
sourcehttp://www.talosintelligence.com/vulnerability_reports/TALOS-2016-0072
titleNetwork Time Protocol ntpq Buffer Overflow Vulnerability

References