Yihan Lian discovered that NTP incorrectly handled certain large request data values. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS. (CVE-2016-2519) Miroslav Lichvar discovered that NTP incorrectly handled certain spoofed addresses when performing rate limiting. A remote attacker could possibly use this issue to perform a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2016-7426) Matthew Van Gundy discovered that NTP incorrectly handled certain crafted broadcast mode packets. A remote attacker could possibly use this issue to perform a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2016-7427, CVE-2016-7428) Miroslav Lichvar discovered that NTP incorrectly handled certain responses. A remote attacker could possibly use this issue to perform a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2016-7429) Sharon Goldberg and Aanchal Malhotra discovered that NTP incorrectly handled origin timestamps of zero. A remote attacker could possibly use this issue to bypass the origin timestamp protection mechanism. This issue only affected Ubuntu 16.10. (CVE-2016-7431) Brian Utterback, Sharon Goldberg and Aanchal Malhotra discovered that NTP incorrectly performed initial sync calculations. This issue only applied to Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-7433) Magnus Stubman discovered that NTP incorrectly handled certain mrulist queries. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-7434) Matthew Van Gund discovered that NTP incorrectly handled origin timestamp checks. A remote attacker could possibly use this issue to perform a denial of service. This issue only affected Ubuntu Ubuntu 16.10, and Ubuntu 17.04. (CVE-2016-9042) Matthew Van Gundy discovered that NTP incorrectly handled certain control mode packets. A remote attacker could use this issue to set or unset traps. This issue only applied to Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-9310) Matthew Van Gundy discovered that NTP incorrectly handled the trap service. A remote attacker could possibly use this issue to cause NTP to crash, resulting in a denial of service. This issue only applied to Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-9311) It was discovered that NTP incorrectly handled memory when processing long variables. A remote authenticated user could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2017-6458) It was discovered that NTP incorrectly handled memory when processing long variables. A remote authenticated user could possibly use this issue to cause NTP to crash, resulting in a denial of service. This issue only applied to Ubuntu 16.04 LTS, Ubuntu 16.10 and Ubuntu 17.04. (CVE-2017-6460) It was discovered that the NTP legacy DPTS refclock driver incorrectly handled the /dev/datum device. A local attacker could possibly use this issue to cause a denial of service. (CVE-2017-6462) It was discovered that NTP incorrectly handled certain invalid settings in a :config directive. A remote authenticated user could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2017-6463) It was discovered that NTP incorrectly handled certain invalid mode configuration directives. A remote authenticated user could possibly use this issue to cause NTP to crash, resulting in a denial of service. (CVE-2017-6464)

It was discovered that NSS incorrectly handled certain empty SSLv2 messages. A remote attacker could possibly use this issue to cause NSS to crash, resulting in a denial of service.

Multiple security issues were discovered in Thunderbird. If a user were tricked in to opening a specially crafted message, an attacker could potentially exploit these to read uninitialized memory, cause a denial of service via application crash, or execute arbitrary code. (CVE-2017-5429, CVE-2017-5430, CVE-2017-5436, CVE-2017-5443, CVE-2017-5444, CVE-2017-5445, CVE-2017-5446, CVE-2017-5447, CVE-2017-5461, CVE-2017-5467) Multiple security issues were discovered in Thunderbird. If a user were tricked in to opening a specially crafted website in a browsing context, an attacker could potentially exploit these to spoof the addressbar contents, conduct cross-site scripting (XSS) attacks, cause a denial of service via application crash, or execute arbitrary code. (CVE-2017-5432, CVE-2017-5433, CVE-2017-5434, CVE-2017-5435, CVE-2017-5437, CVE-2017-5438, CVE-2017-5439, CVE-2017-5440, CVE-2017-5441, CVE-2017-5442, CVE-2017-5449, CVE-2017-5451, CVE-2017-5454, CVE-2017-5459, CVE-2017-5460, CVE-2017-5464, CVE-2017-5465, CVE-2017-5466, CVE-2017-5469, CVE-2016-10195, CVE-2016-10196, CVE-2016-10197) A flaw was discovered in the DRBG number generation in NSS. If an attacker were able to perform a machine-in-the-middle attack, this flaw could potentially be exploited to view sensitive information. (CVE-2017-5462)

Tyler Hicks discovered that LightDM did not confine the user session for guest users. An attacker with physical access could use this issue to access files and other resources that they should not be able to access. In the default installation, this includes files in the home directories of other users on the system. This update fixes the issue by disabling the guest session. It may be re-enabled in a future update. Please see the bug referenced below for instructions on how to manually re-enable the guest session.

Karthik Bhargavan and Gaetan Leurent discovered that the DES and Triple DES ciphers were vulnerable to birthday attacks. A remote attacker could possibly use this flaw to obtain clear text data from long encrypted sessions. This update causes NSS to limit use of the same symmetric key. (CVE-2016-2183) It was discovered that NSS incorrectly handled Base64 decoding. A remote attacker could use this flaw to cause NSS to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2017-5461) This update refreshes the NSS package to version 3.28.4 which includes the latest CA certificate bundle.

Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to read uninitialized memory, obtain sensitive information, spoof the addressbar contents or other UI elements, escape the sandbox to read local files, conduct cross-site scripting (XSS) attacks, cause a denial of service via application crash, or execute arbitrary code. (CVE-2017-5429, CVE-2017-5430, CVE-2017-5432, CVE-2017-5433, CVE-2017-5434, CVE-2017-5435, CVE-2017-5436, CVE-2017-5437, CVE-2017-5438, CVE-2017-5439, CVE-2017-5440, CVE-2017-5441, CVE-2017-5442, CVE-2017-5443, CVE-2017-5444, CVE-2017-5445, CVE-2017-5446, CVE-2017-5447, CVE-2017-5448, CVE-2017-5449, CVE-2017-5451, CVE-2017-5453, CVE-2017-5454, CVE-2017-5455, CVE-2017-5456, CVE-2017-5458, CVE-2017-5459, CVE-2017-5460, CVE-2017-5461, CVE-2017-5464, CVE-2017-5465, CVE-2017-5466, CVE-2017-5467, CVE-2017-5468, CVE-2017-5469) A flaw was discovered in the DRBG number generation in NSS. If an attacker were able to perform a machine-in-the-middle attack, this flaw could potentially be exploited to view sensitive information. (CVE-2017-5462)

Stéphane Graber discovered that AppArmor incorrectly unloaded some profiles when restarted or upgraded, contrary to expected behavior.

Guido Vranken discovered that libevent incorrectly handled memory when processing certain data. A remote attacker could possibly use this issue with an application that uses libevent to cause a denial of service, or possibly execute arbitrary code.

Stefan Buehler discovered that GnuTLS incorrectly verified the serial length of OCSP responses. A remote attacker could possibly use this issue to bypass certain certificate validation measures. This issue only applied to Ubuntu 16.04 LTS. (CVE-2016-7444) Shi Lei discovered that GnuTLS incorrectly handled certain warning alerts. A remote attacker could possibly use this issue to cause GnuTLS to hang, resulting in a denial of service. This issue has only been addressed in Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2016-8610) It was discovered that GnuTLS incorrectly decoded X.509 certificates with a Proxy Certificate Information extension. A remote attacker could use this issue to cause GnuTLS to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2017-5334) It was discovered that GnuTLS incorrectly handled certain OpenPGP certificates. A remote attacker could possibly use this issue to cause GnuTLS to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2017-5335, CVE-2017-5336, CVE-2017-5337)

Guido Vranken discovered that OpenSSL used undefined behaviour when performing pointer arithmetic. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only applied to Ubuntu 12.04 LTS and Ubuntu 14.04 LTS as other releases were fixed in a previous security update. (CVE-2016-2177) It was discovered that OpenSSL did not properly handle Montgomery multiplication, resulting in incorrect results leading to transient failures. This issue only applied to Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2016-7055) It was discovered that OpenSSL did not properly use constant-time operations when performing ECDSA P-256 signing. A remote attacker could possibly use this issue to perform a timing attack and recover private ECDSA keys. This issue only applied to Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-7056) Shi Lei discovered that OpenSSL incorrectly handled certain warning alerts. A remote attacker could possibly use this issue to cause OpenSSL to stop responding, resulting in a denial of service. (CVE-2016-8610) Robert Święcki discovered that OpenSSL incorrectly handled certain truncated packets. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2017-3731) It was discovered that OpenSSL incorrectly performed the x8664 Montgomery squaring procedure. While unlikely, a remote attacker could possibly use this issue to recover private keys. This issue only applied to Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2017-3732)

Karthik Bhargavan and Gaetan Leurent discovered that the DES and Triple DES ciphers were vulnerable to birthday attacks. A remote attacker could possibly use this flaw to obtain clear text data from long encrypted sessions. This update moves those algorithms to the legacy algorithm set and causes them to be used only if no non-legacy algorithms can be negotiated. (CVE-2016-2183) It was discovered that OpenJDK accepted ECSDA signatures using non-canonical DER encoding. An attacker could use this to modify or expose sensitive data. (CVE-2016-5546) It was discovered that OpenJDK did not properly verify object identifier (OID) length when reading Distinguished Encoding Rules (DER) records, as used in x.509 certificates and elsewhere. An attacker could use this to cause a denial of service (memory consumption). (CVE-2016-5547) It was discovered that covert timing channel vulnerabilities existed in the DSA and ECDSA implementations in OpenJDK. A remote attacker could use this to expose sensitive information. (CVE-2016-5548, CVE-2016-5549) It was discovered that the URLStreamHandler class in OpenJDK did not properly parse user information from a URL. A remote attacker could use this to expose sensitive information. (CVE-2016-5552) It was discovered that the URLClassLoader class in OpenJDK did not properly check access control context when downloading class files. A remote attacker could use this to expose sensitive information. (CVE-2017-3231) It was discovered that the Remote Method Invocation (RMI) implementation in OpenJDK performed deserialization of untrusted inputs. A remote attacker could use this to execute arbitrary code. (CVE-2017-3241) It was discovered that the Java Authentication and Authorization Service (JAAS) component of OpenJDK did not properly perform user search LDAP queries. An attacker could use a specially constructed LDAP entry to expose or modify sensitive information. (CVE-2017-3252) It was discovered that the PNGImageReader class in OpenJDK did not properly handle iTXt and zTXt chunks. An attacker could use this to cause a denial of service (memory consumption). (CVE-2017-3253) It was discovered that integer overflows existed in the SocketInputStream and SocketOutputStream classes of OpenJDK. An attacker could use this to expose sensitive information. (CVE-2017-3261) It was discovered that the atomic field updaters in the java.util.concurrent.atomic package in OpenJDK did not properly restrict access to protected field members. An attacker could use this to specially craft a Java application or applet that could bypass Java sandbox restrictions. (CVE-2017-3272) It was discovered that a vulnerability existed in the class construction implementation in OpenJDK. An attacker could use this to specially craft a Java application or applet that could bypass Java sandbox restrictions. (CVE-2017-3289)

It was discovered that a race condition existed in the memory manager of the Linux kernel when handling copy-on-write breakage of private read-only memory mappings. A local attacker could use this to gain administrative privileges.

It was discovered that a race condition existed in the memory manager of the Linux kernel when handling copy-on-write breakage of private read-only memory mappings. A local attacker could use this to gain administrative privileges.