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 •
CVSS: 7.5EPSS: 0%CPEs: 4EXPL: 1CVE-2021-28682 – envoyproxy/envoy: integer overflow handling large grpc-timeouts
https://notcve.org/view.php?id=CVE-2021-28682
An issue was discovered in Envoy through 1.71.1. There is a remotely exploitable integer overflow in which a very large grpc-timeout value leads to unexpected timeout calculations. Se detectó un problema en Envoy versiones hasta 1.71.1. presenta un desbordamiento de enteros explotable remoto en el que un valor de grpc-timeout muy grande conlleva a cálculos de tiempo de espera inesperados A flaw was found in envoyproxy/envoy. An attacker, able to craft a packet which specifies a large grpc-timeout, can potentially cause envoy to incorrectly calculate the timeouts resulting in a denial of service. • https://blog.envoyproxy.io https://github.com/envoyproxy/envoy/blob/15e3b9dbcc9aaa9d391fa8033904aad1ea1ae70d/api/envoy/api/v2/cluster.proto#L36 https://github.com/envoyproxy/envoy/releases https://github.com/envoyproxy/envoy/security/advisories/GHSA-r22g-5f3x-xjgg https://access.redhat.com/security/cve/CVE-2021-28682 https://bugzilla.redhat.com/show_bug.cgi?id=1942272 • CWE-190: Integer Overflow or Wraparound •
CVSS: 7.5EPSS: 0%CPEs: 2EXPL: 0CVE-2021-28683 – envoyproxy/envoy: NULL pointer dereference in TLS alert code handling
https://notcve.org/view.php?id=CVE-2021-28683
An issue was discovered in Envoy through 1.71.1. There is a remotely exploitable NULL pointer dereference and crash in TLS when an unknown TLS alert code is received. Se detectó un problema en Envoy versiones hasta 1.71.1. Se presenta una desreferencia de puntero NULL explotable remoto y bloqueo en TLS cuando es recibido un código de alerta TLS desconocido A NULL pointer dereference vulnerability was found envoyproxy/envoy. This flaw allows an attacker to establish a TLS session that sends an invalid TLS alert code, causing a NULL pointer exception to occur that crashes the application, resulting in a denial of service. • https://blog.envoyproxy.io https://github.com/envoyproxy/envoy/releases https://github.com/envoyproxy/envoy/security/advisories/GHSA-r22g-5f3x-xjgg https://github.com/envoyproxy/envoy/security/advisories/GHSA-xw4q-6pj2-5gfg https://access.redhat.com/security/cve/CVE-2021-28683 https://bugzilla.redhat.com/show_bug.cgi?id=1942263 • CWE-476: NULL Pointer Dereference •