compression is a Node.js and Express compression middleware. In versions before 1.8.2, when a client aborts the connection while a compressed response is still being sent, the zlib stream created to compress that response is never destroyed, so each aborted compressed response leaks its native zlib memory. A remote unauthenticated attacker can repeatedly open requests and disconnect early, exhausting the available memory and crashing the server. All applications using compression are affected. The issue is fixed in compression 1.8.2, and users should upgrade to 1.8.2 or later.

Impact

A vulnerability in compression < 1.8.2 allows an attacker to trigger a Denial of Service (DoS) by disconnecting while a compressed response is being sent. When the client aborts the connection before the response finishes, the zlib stream created to compress that response is never destroyed, so each aborted compressed response leaks its native zlib memory. Repeated aborted requests can exhaust available memory. All applications using compression are affected.

Patches

Users should upgrade to 1.8.2.

Workarounds

None.