inets in Erlang possibly 22.1 and earlier follows RFC 3875 section 4.1.18 and therefore does not protect applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect an application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue.
An issue was discovered in Erlang/OTP 18.x. Erlang's generation of compiled regular expressions is vulnerable to a heap overflow. Regular expressions using a malformed extpattern can indirectly specify an offset that is used as an array index. This ordinal permits arbitrary regions within the erts_alloc arena to be both read and written to.