amphp/http will collect HTTP/2 CONTINUATION frames in an unbounded buffer and will not check the header size limit until it has received the END_HEADERS flag, resulting in an OOM crash. amphp/http-client and amphp/http-server are indirectly affected if they're used with an unpatched version of amphp/http. Early versions of amphp/http-client with HTTP/2 support (v4.0.0-rc10 to 4.0.0) are also directly affected.
Acknowledgements
Thank you to Bartek Nowotarski for reporting the vulnerability.
amphp/httpwill collect HTTP/2CONTINUATIONframes in an unbounded buffer and will not check the header size limit until it has received theEND_HEADERSflag, resulting in an OOM crash.amphp/http-clientandamphp/http-serverare indirectly affected if they're used with an unpatched version ofamphp/http. Early versions ofamphp/http-clientwith HTTP/2 support (v4.0.0-rc10 to 4.0.0) are also directly affected.Acknowledgements
Thank you to Bartek Nowotarski for reporting the vulnerability.