Apache Traffic Server 9.2.16, 10.1.5 and 10.2.1 fix the 15 security vulnerabilities listed below. They affect releases up to and including 9.2.15, 10.1.4 and 10.2.0 — among them request-smuggling, memory-safety, and access-control issues, the most serious rated CVSS 10.0. Fixed releases are available now, and all users are strongly encouraged to upgrade promptly.
How to read this: Severity is the Apache rating — the impact and exploitability of the issue in a default configuration. CVSS is the technical base score, which can be higher for issues that need specific conditions or a non-default configuration to reach.
Apache Traffic Server's experimental magick plugin lets an unauthenticated client control ImageMagick convert arguments in its default (unsigned) configuration.
Apache Traffic Server's experimental wasm plugin has a use-after-free in its transaction-close handler and forwards unvalidated guest-supplied metric IDs to the internal stats API.
Apache Traffic Server's default outbound session-sharing policy can reuse a pooled TLS session authenticated with one client certificate for a transaction configured to present a different one.
Apache Traffic Server can resume a TLS session across SNI virtual hosts without re-verifying a client certificate required by the resumed host's verify_client STRICT policy.
Apache Traffic Server forwarded a malformed 302 response that should have been rejected as a parse error, because the Transfer-Encoding: chunked carve-out bypassed the rejection path. A response that two peers can read differently is then stored and served, allowing cache poisoning and response-framing desync.
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.
When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users.
Apache Traffic Server can be used to exhaust an HTTP/1.1 origin's worker pool via a truncated HTTP/2 Content-Length value.
Apache Traffic Server can be used to exhaust an HTTP/1.1 origin's worker pool via a malformed padded HTTP/2 DATA frame.
Apache Traffic Server 9.2.15, 10.1.4 and 10.2.0 write one unthrottled diagnostic log line for every internal @ header they strip, so a request carrying many such headers makes the proxy write far more log data than the request contains.
Apache Traffic Server's origin_server_auth plugin lets a client force signing of attacker-chosen AWS request headers under the proxy's own credentials.
Apache Traffic Server allows request smuggling via HEAD requests that carry Content-Length or Transfer-Encoding.
Apache Traffic Server's experimental tsmemcache plugin allows unauthenticated network read, write, and deletion of the shared proxy cache.
Apache Traffic Server can crash with a null pointer dereference when a client POST request is torn down via half-close while a chunked origin response is being reparsed from a reentrant write-ready callback, a timing-dependent race.
Apache Traffic Server can stall a chunked transfer that it passes through with its trailers removed (proxy.config.http.drop_chunked_trailers) until the connection times out, because it waits for the trailer bytes it has already dropped. Trailer dropping is on by default in 10.x. In 9.2.x it is off by default, and those versions are affected only if it is enabled.