CVSS: 7.5EPSS: 0%CPEs: 4EXPL: 0CVE-2021-32778 – Excessive CPU utilization when closing HTTP/2 streams
https://notcve.org/view.php?id=CVE-2021-32778
Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions envoy’s procedure for resetting a HTTP/2 stream has O(N^2) complexity, leading to high CPU utilization when a large number of streams are reset. Deployments are susceptible to Denial of Service when Envoy is configured with high limit on H/2 concurrent streams. An attacker wishing to exploit this vulnerability would require a client opening and closing a large number of H/2 streams. Envoy versions 1.19.1, 1.18.4, 1.17.4, 1.16.5 contain fixes to reduce time complexity of resetting HTTP/2 streams. • https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history • CWE-834: Excessive Iteration •
CVSS: 8.6EPSS: 0%CPEs: 4EXPL: 0CVE-2021-32777 – Incorrect concatenation of multiple value request headers in ext-authz extension
https://notcve.org/view.php?id=CVE-2021-32777
Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions when ext-authz extension is sending request headers to the external authorization service it must merge multiple value headers according to the HTTP spec. However, only the last header value is sent. This may allow specifically crafted requests to bypass authorization. Attackers may be able to escalate privileges when using ext-authz extension or back end service that uses multiple value headers for authorization. • https://github.com/envoyproxy/envoy/security/advisories/GHSA-6g4j-5vrw-2m8h https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history https://access.redhat.com/security/cve/CVE-2021-32777 https://bugzilla.redhat.com/show_bug.cgi?id=1996933 • CWE-551: Incorrect Behavior Order: Authorization Before Parsing and Canonicalization CWE-863: Incorrect Authorization •
CVSS: 8.3EPSS: 0%CPEs: 4EXPL: 0CVE-2021-29492 – Bypass of path matching rules using escaped slash characters
https://notcve.org/view.php?id=CVE-2021-29492
Envoy is a cloud-native edge/middle/service proxy. Envoy does not decode escaped slash sequences `%2F` and `%5C` in HTTP URL paths in versions 1.18.2 and before. A remote attacker may craft a path with escaped slashes, e.g. `/something%2F..%2Fadmin`, to bypass access control, e.g. a block on `/admin`. A backend server could then decode slash sequences and normalize path and provide an attacker access beyond the scope provided for by the access control policy. ### Impact Escalation of Privileges when using RBAC or JWT filters with enforcement based on URL path. • https://github.com/envoyproxy/envoy/security/advisories/GHSA-4987-27fx-x6cf https://access.redhat.com/security/cve/CVE-2021-29492 https://bugzilla.redhat.com/show_bug.cgi?id=1951188 • CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE-863: Incorrect Authorization •