Search for vulnerabilities
| Vulnerability ID | VCID-jztw-yc9e-aaaa |
| Aliases |
CVE-2021-32778
|
| Summary | 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. As a workaround users may limit the number of simultaneous HTTP/2 dreams for upstream and downstream peers to a low number, i.e. 100. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 8.0 |
| Risk | 4.0 |
| Affected and Fixed Packages | Package Details |
| CWE-834 | Excessive Iteration |
| CWE-400 | Uncontrolled Resource Consumption |
| Reference id | Reference type | URL |
|---|---|---|
| https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-32778.json | ||
| https://api.first.org/data/v1/epss?cve=CVE-2021-32778 | ||
| https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc | ||
| https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history | ||
| AVG-2321 | https://security.archlinux.org/AVG-2321 | |
| cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* | https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* | |
| cpe:2.3:a:envoyproxy:envoy:1.19.0:*:*:*:*:*:*:* | https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:envoyproxy:envoy:1.19.0:*:*:*:*:*:*:* | |
| CVE-2021-32778 | https://nvd.nist.gov/vuln/detail/CVE-2021-32778 | |
| ISTIO-SECURITY-2021-008 | https://istio.io/latest/news/security/ISTIO-SECURITY-2021-008/ | |
| RHEA-2021:4051 | https://bugzilla.redhat.com/show_bug.cgi?id=1996946 |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
| Exploitability (E) | Access Vector (AV) | Access Complexity (AC) | Authentication (Au) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|
high functional unproven proof_of_concept not_defined |
local adjacent_network network |
high medium low |
multiple single none |
none partial complete |
none partial complete |
none partial complete |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
| Percentile | 0.22169 |
| EPSS Score | 0.0007 |
| Published At | June 20, 2025, 12:55 p.m. |
| Date | Actor | Action | Source | VulnerableCode Version |
|---|---|---|---|---|
| There are no relevant records. | ||||