Several security issues were fixed in mbedtls.
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)
5 February 2020
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in mbedtls.
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)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.