CRLF injection vulnerability in the on_req function in lib/handler/redirect.c in H2O before 1.6.2 and 1.7.x before 1.7.0-beta3 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a crafted URI.
3.7CVSS
4.3AI Score
0.005EPSS
lib/http2/connection.c in H2O before 1.7.3 and 2.x before 2.0.0-beta5 mishandles HTTP/2 disconnection, which allows remote attackers to cause a denial of service (use-after-free and application crash) or possibly execute arbitrary code via a crafted packet.
7.5CVSS
8AI Score
0.012EPSS
H2O versions 2.0.3 and earlier and 2.1.0-beta2 and earlier allows remote attackers to cause a denial-of-service (DoS) via format string specifiers in a template file via fastcgi, mruby, proxy, redirect or reproxy.
7.5CVSS
7.3AI Score
0.001EPSS
Use-after-free vulnerability in H2O allows remote attackers to cause a denial-of-service (DoS) or obtain server certificate private keys and possibly other information.
9.1CVSS
9.1AI Score
0.004EPSS
H2O version 2.2.2 and earlier allows remote attackers to cause a denial of service in the server via specially crafted HTTP/1 header.
7.5CVSS
7.2AI Score
0.001EPSS
Buffer overflow in H2O version 2.2.2 and earlier allows remote attackers to cause a denial-of-service in the server via unspecified vectors.
7.5CVSS
7.4AI Score
0.002EPSS
H2O version 2.2.3 and earlier allows remote attackers to cause a denial of service in the server via unspecified vectors.
6.5CVSS
6.4AI Score
0.001EPSS
H2O version 2.2.3 and earlier allows remote attackers to cause a denial of service in the server via specially crafted HTTP/2 header.
7.5CVSS
7.3AI Score
0.001EPSS
Buffer overflow in H2O version 2.2.4 and earlier allows remote attackers to execute arbitrary code or cause a denial of service (DoS) via unspecified vectors.
9.8CVSS
9.8AI Score
0.023EPSS
h2o is an open source http server. In code prior to the 8c0eca3 commit h2o may attempt to access uninitialized memory. When receiving QUIC frames in certain order, HTTP/3 server-side implementation of h2o can be misguided to treat uninitialized memory as HTTP/3 frames that have been received. When ...
7.4CVSS
5.6AI Score
0.001EPSS
H2O is an HTTP server. In versions 2.3.0-beta2 and prior, when the reverse proxy handler tries to processes a certain type of invalid HTTP request, it tries to build an upstream URL by reading from uninitialized pointer. This behavior can lead to crashes or leak of information to back end HTTP serv...
8.2CVSS
7.9AI Score
0.002EPSS
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. In version 2.3.0-beta2 and prior, when h2o is configured to listen to multiple addresses or ports with each of them using different backend servers managed by multiple entities, a malicious backend entity that also has the opportun...
6.7CVSS
6.4AI Score
0.0004EPSS
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The QUIC stack (quicly), as used by H2O up to commit 43f86e5 (in version 2.3.0-beta and prior), is susceptible to a state exhaustion attack. When H2O is serving HTTP/3, a remote attacker can exploit this vulnerability to progressiv...
7.5CVSS
7.4AI Score
0.001EPSS