7.5 - USN-4267-1

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in mbedtls.

Software Description: - mbedtls: lightweight crypto and SSL/TLS library - crypto library

Details:

It was discovered that mbedtls has a bounds-check bypass through an integer overflow that can be used by an attacked to execute arbitrary code or cause a denial of service. (CVE-2017-18187)

It was discovered that mbedtls has a vulnerability where an attacker could execute arbitrary code or cause a denial of service (buffer overflow) via a crafted certificate chain that is mishandled during RSASSA-PSS signature verification within a TLS or DTLS session. (CVE-2018-0487)

It was discovered that mbedtls has a vulnerability where an attacker could execute arbitrary code or cause a denial of service (heap corruption) via a crafted application packet within a TLS or DTLS session. (CVE-2018-0488)

It was discovered that mbedtls has a vulnerability that allows remote attackers to achieve partial plaintext recovery (for a CBC based ciphersuite) via a timing-based side-channel attack. (CVE-2018-0497)

It was discovered that mbedtls has a vulnerability that allows local users to achieve partial plaintext recovery (for a CBC based ciphersuite) via a cache-based side-channel attack. (CVE-2018-0498)

Update instructions:

The problem can be corrected by updating your system to the following package versions:

Ubuntu 16.04 LTS:
libmbedcrypto0 2.2.1-2ubuntu0.3
libmbedtls10 2.2.1-2ubuntu0.3
libmbedx509-0 2.2.1-2ubuntu0.3

In general, a standard system update will make all the necessary changes.

References:
https://usn.ubuntu.com/4267-1
CVE-2017-18187, CVE-2018-0487, CVE-2018-0488, CVE-2018-0497,
CVE-2018-0498

Package Information:
https://launchpad.net/ubuntu/+source/mbedtls/2.2.1-2ubuntu0.3