ID CVE-2015-3238
Summary The _unix_run_helper_binary function in the pam_unix module in Linux-PAM (aka pam) before 1.2.1, when unable to directly access passwords, allows local users to enumerate usernames or cause a denial of service (hang) via a large password.
References
Vulnerable Configurations
  • Linux-PAM 1.1.8
    cpe:2.3:a:linux-pam:linux-pam:1.1.8
  • Oracle Sparc-OPL Service Processor 1121
    cpe:2.3:a:oracle:sparc-opl_service_processor:1121
CVSS
Base: 5.8 (as of 14-06-2016 - 14:05)
Impact:
Exploitability:
CWE CWE-200
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.
  • Reusing Session IDs (aka Session Replay)
    This attack targets the reuse of valid session ID to spoof the target system in order to gain privileges. The attacker tries to reuse a stolen session ID used previously during a transaction to perform spoofing and session hijacking. Another name for this type of attack is Session Replay.
  • Using Slashes in Alternate Encoding
    This attack targets the encoding of the Slash characters. An attacker would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the attacker many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.
Access
VectorComplexityAuthentication
NETWORK MEDIUM NONE
Impact
ConfidentialityIntegrityAvailability
PARTIAL NONE PARTIAL
nessus via4
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-2935-2.NASL
    description USN-2935-1 fixed vulnerabilities in PAM. The updates contained a packaging change that prevented upgrades in certain multiarch environments. This update fixes the problem. We apologize for the inconvenience. It was discovered that the PAM pam_userdb module incorrectly used a case-insensitive method when comparing hashed passwords. A local attacker could possibly use this issue to make brute-force attacks easier. This issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2013-7041) Sebastian Krahmer discovered that the PAM pam_timestamp module incorrectly performed filtering. A local attacker could use this issue to create arbitrary files, or possibly bypass authentication. This issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2014-2583) Sebastien Macke discovered that the PAM pam_unix module incorrectly handled large passwords. A local attacker could possibly use this issue in certain environments to enumerate usernames or cause a denial of service. (CVE-2015-3238). 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 seen 2019-02-21
    modified 2018-12-01
    plugin id 89997
    published 2016-03-17
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=89997
    title Ubuntu 12.04 LTS / 14.04 LTS / 15.10 : pam regression (USN-2935-2)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_SU-2016-1645-1.NASL
    description This update for pam fixes two security issues. These security issues were fixed : - CVE-2015-3238: pam_unix in conjunction with SELinux allowed for DoS attacks (bsc#934920). - CVE-2013-7041: Compare password hashes case-sensitively (bsc#854480). 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 seen 2019-02-21
    modified 2018-11-29
    plugin id 93163
    published 2016-08-29
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=93163
    title SUSE SLES11 Security Update : pam (SUSE-SU-2016:1645-1)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2015-10830.NASL
    description Update fixing a minor security issue CVE-2015-3238. 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 2019-02-21
    modified 2016-10-18
    plugin id 84481
    published 2015-07-01
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=84481
    title Fedora 22 : pam-1.1.8-19.fc22 (2015-10830)
  • NASL family CentOS Local Security Checks
    NASL id CENTOS_RHSA-2015-1640.NASL
    description An updated pam package that fixes one security issue is now available for Red Hat Enterprise Linux 6 and 7. Red Hat Product Security has rated this update as having Moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. Pluggable Authentication Modules (PAM) provide a system whereby administrators can set up authentication policies without having to recompile programs to handle authentication. It was discovered that the _unix_run_helper_binary() function of PAM's unix_pam module could write to a blocking pipe, possibly causing the function to become unresponsive. An attacker able to supply large passwords to the unix_pam module could use this flaw to enumerate valid user accounts, or cause a denial of service on the system. (CVE-2015-3238) Red Hat would like to thank Sebastien Macke of Trustwave SpiderLabs for reporting this issue. All pam users are advised to upgrade to this updated package, which contains a backported patch to correct this issue.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 85516
    published 2015-08-19
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=85516
    title CentOS 6 / 7 : pam (CESA-2015:1640)
  • NASL family Amazon Linux Local Security Checks
    NASL id ALA_ALAS-2015-589.NASL
    description It was discovered that the _unix_run_helper_binary() function of PAM's unix_pam module could write to a blocking pipe, possibly causing the function to become unresponsive. An attacker able to supply large passwords to the unix_pam module could use this flaw to enumerate valid user accounts, or cause a denial of service on the system. (CVE-2015-3238)
    last seen 2019-02-21
    modified 2018-04-18
    plugin id 85747
    published 2015-09-03
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=85747
    title Amazon Linux AMI : pam (ALAS-2015-589)
  • NASL family F5 Networks Local Security Checks
    NASL id F5_BIGIP_SOL17494.NASL
    description The _unix_run_helper_binary function in the pam_unix module in Linux-PAM (aka pam) before 1.2.1, when unable to directly access passwords, allows local users to enumerate usernames or cause a denial of service (hang) via a large password.
    last seen 2019-02-21
    modified 2019-01-04
    plugin id 88438
    published 2016-01-28
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=88438
    title F5 Networks BIG-IP : PAM vulnerability (SOL17494)
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-2935-1.NASL
    description It was discovered that the PAM pam_userdb module incorrectly used a case-insensitive method when comparing hashed passwords. A local attacker could possibly use this issue to make brute-force attacks easier. This issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2013-7041) Sebastian Krahmer discovered that the PAM pam_timestamp module incorrectly performed filtering. A local attacker could use this issue to create arbitrary files, or possibly bypass authentication. This issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2014-2583) Sebastien Macke discovered that the PAM pam_unix module incorrectly handled large passwords. A local attacker could possibly use this issue in certain environments to enumerate usernames or cause a denial of service. (CVE-2015-3238). 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 seen 2019-02-21
    modified 2018-12-01
    plugin id 89996
    published 2016-03-17
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=89996
    title Ubuntu 12.04 LTS / 14.04 LTS / 15.10 : pam vulnerabilities (USN-2935-1)
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-2935-3.NASL
    description USN-2935-1 fixed vulnerabilities in PAM. The updates contained a packaging change that prevented upgrades in certain multiarch environments. USN-2935-2 intended to fix the problem but was incomplete for Ubuntu 12.04 LTS. This update fixes the problem in Ubuntu 12.04 LTS. We apologize for the inconvenience. It was discovered that the PAM pam_userdb module incorrectly used a case-insensitive method when comparing hashed passwords. A local attacker could possibly use this issue to make brute-force attacks easier. This issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2013-7041) Sebastian Krahmer discovered that the PAM pam_timestamp module incorrectly performed filtering. A local attacker could use this issue to create arbitrary files, or possibly bypass authentication. This issue only affected Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2014-2583) Sebastien Macke discovered that the PAM pam_unix module incorrectly handled large passwords. A local attacker could possibly use this issue in certain environments to enumerate usernames or cause a denial of service. (CVE-2015-3238). 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 seen 2019-02-21
    modified 2018-12-01
    plugin id 90021
    published 2016-03-18
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=90021
    title Ubuntu 12.04 LTS : pam regression (USN-2935-3)
  • NASL family Gentoo Local Security Checks
    NASL id GENTOO_GLSA-201605-05.NASL
    description The remote host is affected by the vulnerability described in GLSA-201605-05 (Linux-PAM: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Linux-PAM. Please review the CVE identifiers referenced below for details. Impact : Remote attackers could cause Denial of Service, conduct brute-force attacks, and conduct username enumeration. Workaround : There is no known workaround at this time.
    last seen 2019-02-21
    modified 2016-10-10
    plugin id 91378
    published 2016-05-31
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=91378
    title GLSA-201605-05 : Linux-PAM: Multiple vulnerabilities
  • NASL family Oracle Linux Local Security Checks
    NASL id ORACLELINUX_ELSA-2015-1640.NASL
    description From Red Hat Security Advisory 2015:1640 : An updated pam package that fixes one security issue is now available for Red Hat Enterprise Linux 6 and 7. Red Hat Product Security has rated this update as having Moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. Pluggable Authentication Modules (PAM) provide a system whereby administrators can set up authentication policies without having to recompile programs to handle authentication. It was discovered that the _unix_run_helper_binary() function of PAM's unix_pam module could write to a blocking pipe, possibly causing the function to become unresponsive. An attacker able to supply large passwords to the unix_pam module could use this flaw to enumerate valid user accounts, or cause a denial of service on the system. (CVE-2015-3238) Red Hat would like to thank Sebastien Macke of Trustwave SpiderLabs for reporting this issue. All pam users are advised to upgrade to this updated package, which contains a backported patch to correct this issue.
    last seen 2019-02-21
    modified 2018-07-26
    plugin id 85526
    published 2015-08-19
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=85526
    title Oracle Linux 6 / 7 : pam (ELSA-2015-1640)
  • NASL family Red Hat Local Security Checks
    NASL id REDHAT-RHSA-2015-1640.NASL
    description An updated pam package that fixes one security issue is now available for Red Hat Enterprise Linux 6 and 7. Red Hat Product Security has rated this update as having Moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. Pluggable Authentication Modules (PAM) provide a system whereby administrators can set up authentication policies without having to recompile programs to handle authentication. It was discovered that the _unix_run_helper_binary() function of PAM's unix_pam module could write to a blocking pipe, possibly causing the function to become unresponsive. An attacker able to supply large passwords to the unix_pam module could use this flaw to enumerate valid user accounts, or cause a denial of service on the system. (CVE-2015-3238) Red Hat would like to thank Sebastien Macke of Trustwave SpiderLabs for reporting this issue. All pam users are advised to upgrade to this updated package, which contains a backported patch to correct this issue.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 85530
    published 2015-08-19
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=85530
    title RHEL 6 / 7 : pam (RHSA-2015:1640)
  • NASL family Huawei Local Security Checks
    NASL id EULEROS_SA-2018-1375.NASL
    description According to the version of the pam package installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerability : - It was discovered that the _unix_run_helper_binary() function of PAM's unix_pam module could write to a blocking pipe, possibly causing the function to become unresponsive. An attacker able to supply large passwords to the unix_pam module could use this flaw to enumerate valid user accounts, or cause a denial of service on the system.(CVE-2015-3238) Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-11-21
    plugin id 119066
    published 2018-11-21
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=119066
    title EulerOS Virtualization 2.5.1 : pam (EulerOS-SA-2018-1375)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2015-10848.NASL
    description Update fixing a minor security issue CVE-2015-3238. 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 2019-02-21
    modified 2016-10-18
    plugin id 84520
    published 2015-07-06
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=84520
    title Fedora 21 : pam-1.1.8-19.fc21 (2015-10848)
  • NASL family Scientific Linux Local Security Checks
    NASL id SL_20150818_PAM_ON_SL6_X.NASL
    description It was discovered that the _unix_run_helper_binary() function of PAM's unix_pam module could write to a blocking pipe, possibly causing the function to become unresponsive. An attacker able to supply large passwords to the unix_pam module could use this flaw to enumerate valid user accounts, or cause a denial of service on the system. (CVE-2015-3238)
    last seen 2019-02-21
    modified 2018-12-28
    plugin id 85564
    published 2015-08-20
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=85564
    title Scientific Linux Security Update : pam on SL6.x, SL7.x i386/x86_64
  • NASL family OracleVM Local Security Checks
    NASL id ORACLEVM_OVMSA-2015-0117.NASL
    description The remote OracleVM system is missing necessary patches to address critical security updates : - fix CVE-2015-3238 - DoS due to blocking pipe with very long password - make pam_pwhistory and pam_unix tolerant of opasswd file corruption - pam_userdb: allow any crypt hash algorithm to be used (#1119289) - pam_cracklib: improve documentation (#889233) - unbreak authentication if ld.so.preload is not empty - correct off by one error in account expiration calculation (#947011) - pam_console_apply: do not print error if console.perms.d is empty - properly handle all cases where crypt might return NULL (#1026203) - pam_limits: clarify documentation of maxsyslogins limit (#1028490) - pam_access: call DNS resolution only when necessary and cache results (#1029817) - pam_limits: nofile applies to file descriptors not files (#1040664) - pam_limits: check whether the utmp login entry is valid (#1054936) - correct URLs in spec file (#1071770) - pam_userdb: correct the example in man page (#1078779) - pam_selinux: canonicalize username for getseuser (#1083981) - pam_access: fix netgroup matching and @user@@netgroup parsing (#740233) - pam_tty_audit: allow for runtime backwards compatibility with old kernels - add option to pam_tty_audit to disable auditing of password input
    last seen 2019-02-21
    modified 2018-07-25
    plugin id 85529
    published 2015-08-19
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=85529
    title OracleVM 3.3 : pam (OVMSA-2015-0117)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_SU-2017-1398-1.NASL
    description This update for pam fixes the following issues : - CVE-2015-3238: pam_unix in conjunction with SELinux allowed for DoS attacks (bsc#934920). - log a hint to syslog if /etc/nologin is present, but empty (bsc#1015565). - If /etc/nologin is present, but empty, log a hint to syslog. (bsc#1015565) - Added support for libowcrypt.so, if present, to configure support for BLOWFISH (bsc#1037824) 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 2019-02-21
    modified 2018-11-30
    plugin id 100408
    published 2017-05-25
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=100408
    title SUSE SLED12 / SLES12 Security Update : pam (SUSE-SU-2017:1398-1)
redhat via4
advisories
bugzilla
id 1228571
title CVE-2015-3238 pam: DoS/user enumeration due to blocking pipe in pam_unix module
oval
OR
  • AND
    • OR
      • comment Red Hat Enterprise Linux 6 Client is installed
        oval oval:com.redhat.rhba:tst:20111656001
      • comment Red Hat Enterprise Linux 6 Server is installed
        oval oval:com.redhat.rhba:tst:20111656002
      • comment Red Hat Enterprise Linux 6 Workstation is installed
        oval oval:com.redhat.rhba:tst:20111656003
      • comment Red Hat Enterprise Linux 6 ComputeNode is installed
        oval oval:com.redhat.rhba:tst:20111656004
    • OR
      • AND
        • comment pam is earlier than 0:1.1.1-20.el6_7.1
          oval oval:com.redhat.rhsa:tst:20151640005
        • comment pam is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20100891006
      • AND
        • comment pam-devel is earlier than 0:1.1.1-20.el6_7.1
          oval oval:com.redhat.rhsa:tst:20151640007
        • comment pam-devel is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20100891008
  • AND
    • OR
      • comment Red Hat Enterprise Linux 7 Client is installed
        oval oval:com.redhat.rhba:tst:20150364001
      • comment Red Hat Enterprise Linux 7 Server is installed
        oval oval:com.redhat.rhba:tst:20150364002
      • comment Red Hat Enterprise Linux 7 Workstation is installed
        oval oval:com.redhat.rhba:tst:20150364003
      • comment Red Hat Enterprise Linux 7 ComputeNode is installed
        oval oval:com.redhat.rhba:tst:20150364004
    • OR
      • AND
        • comment pam is earlier than 0:1.1.8-12.el7_1.1
          oval oval:com.redhat.rhsa:tst:20151640013
        • comment pam is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20100891006
      • AND
        • comment pam-devel is earlier than 0:1.1.8-12.el7_1.1
          oval oval:com.redhat.rhsa:tst:20151640014
        • comment pam-devel is signed with Red Hat redhatrelease2 key
          oval oval:com.redhat.rhsa:tst:20100891008
rhsa
id RHSA-2015:1640
released 2015-08-18
severity Moderate
title RHSA-2015:1640: pam security update (Moderate)
rpms
  • pam-0:1.1.1-20.el6_7.1
  • pam-devel-0:1.1.1-20.el6_7.1
  • pam-0:1.1.8-12.el7_1.1
  • pam-devel-0:1.1.8-12.el7_1.1
refmap via4
bid 75428
confirm
fedora
  • FEDORA-2015-10830
  • FEDORA-2015-10848
gentoo GLSA-201605-05
misc
mlist [oss-security] 20150625 Linux-PAM 1.2.1 released to address CVE-2015-3238
ubuntu
  • USN-2935-1
  • USN-2935-2
  • USN-2935-3
Last major update 02-12-2016 - 22:09
Published 24-08-2015 - 10:59
Last modified 03-01-2019 - 10:01
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