Package Instance

Composer is vulnerable to ANSI sequence injection
Attackers controlling remote sources that Composer downloads from might in some way inject ANSI control characters in the terminal output of various Composer commands, causing mangled output and potentially leading to confusion or DoS of the terminal application.

There is no proven exploit and this has thus a low severity but Composer still published a CVE as it has potential for abuse, and Composer wants to be on the safe side informing users that they should upgrade.

Improper Input Validation
Composer is a dependency manager for the PHP programming language. Integrators using Composer code to call `VcsDriver::getFileContent` can have a code injection vulnerability if the user can control the `$file` or `$identifier` argument. This leads to a vulnerability on packagist.org for example where the composer.json's `readme` field can be used as a vector for injecting parameters into hg/Mercurial via the `$file` argument, or git via the `$identifier` argument if you allow arbitrary data there (Packagist does not, but maybe other integrators do). Composer itself should not be affected by the vulnerability as it does not call `getFileContent` with arbitrary data into `$file`/`$identifier`. To the best of our knowledge this was not abused, and the vulnerability has been patched on packagist.org and Private Packagist within a day of the vulnerability report.

Composer Remote Code Execution vulnerability via web-accessible composer.phar
Users publishing a composer.phar to a public web-accessible server where the composer.phar can be executed as a php file may be impacted if PHP also has `register_argc_argv` enabled in php.ini.