If ALTSVC frame is received by libnghttp2 and it is larger than it can accept, the pointer field which points to ALTSVC frame payload is left NULL. Later libnghttp2 attempts to access another field through the pointer, and gets segmentation fault. The largest frame size libnghttp2 accept is by default 16384 bytes. Receiving ALTSVC frame is disabled by default. Application has to enable it explicitly by calling `nghttp2_option_set_builtin_recv_extension_type(opt, NGHTTP2_ALTSVC)`. Transmission of ALTSVC is always enabled, and it does not cause this vulnerability. ALTSVC frame is expected to be sent by server, and received by client as defined in RFC 7838. Affected versions: nghttp2 >= 1.10.0 and nghttp2 <= v1.31.0
Acknowledgments: Name: the Nghttp2 project
Created attachment 1419700 [details] Upstream patch
Although rh-nodejs8-nodejs includes nghttp2, it is not affected: support for the ALTSVC frame was added in 9.4.0 via https://github.com/nodejs/node/commit/ce22d6f9178507c7a41b04ac4097b9ea902049e3#diff-8d67cefebb5e07f8f3cad3c90c402bb2
Public via: http://www.openwall.com/lists/oss-security/2018/04/12/4
Created nghttp2 tracking bugs for this issue: Affects: fedora-all [bug 1566990] Affects: epel-7 [bug 1566989]
This issue has been addressed in the following products: Red Hat JBoss Core Services Via RHSA-2019:0366 https://access.redhat.com/errata/RHSA-2019:0366
This issue has been addressed in the following products: JBoss Core Services on RHEL 6 JBoss Core Services on RHEL 7 Via RHSA-2019:0367 https://access.redhat.com/errata/RHSA-2019:0367