Accessibility. A privacy issue was addressed with improved private data redaction for log entries.

It was discovered that websocket-extensions does not properly parse special headers. A remote attacker could use this issue to cause regex backtracking, resulting in a denial of service. (CVE-2020-7663)

Fabian Vogt discovered that Ark incorrectly handled symbolic links in tar archive files. An attacker could use this to construct a malicious tar archive that, when opened, would create files outside the extraction directory.

It was discovered that Mutt incorrectly handled certain requests. An attacker could possibly use this issue to enable MITM attacks. (CVE-2020-14954) This update also address a regression caused in the last update USN-4401-1. It only affected Ubuntu 12.04 ESM, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS and Ubuntu 19.10.