Vulnerability Name:

CVE-2021-32780 (CCN-208233)

Assigned:2021-08-24
Published:2021-08-24
Updated:2022-06-15
Summary:Envoy is an open source L7 proxy and communication bus designed for large modern service oriented architectures. In affected versions Envoy transitions a H/2 connection to the CLOSED state when it receives a GOAWAY frame without any streams outstanding. The connection state is transitioned to DRAINING when it receives a SETTING frame with the SETTINGS_MAX_CONCURRENT_STREAMS parameter set to 0. Receiving these two frames in the same I/O event results in abnormal termination of the Envoy process due to invalid state transition from CLOSED to DRAINING. A sequence of H/2 frames delivered by an untrusted upstream server will result in Denial of Service in the presence of untrusted **upstream** servers. Envoy versions 1.19.1, 1.18.4 contain fixes to stop processing of pending H/2 frames after connection transition to the CLOSED state.
CVSS v3 Severity:7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
8.6 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)
7.5 High (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Changed
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
CVSS v2 Severity:5.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Partial
7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-754
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2021-32780

Source: XF
Type: UNKNOWN
envoy-cve202132780-dos(208233)

Source: CCN
Type: Envoy GIT Repository
Incorrect handling of H/2 GOAWAY followed by SETTINGS frames

Source: CONFIRM
Type: Third Party Advisory
https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8

Source: MISC
Type: Vendor Advisory
https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history

Source: CCN
Type: WhiteSource Vulnerability Database
CVE-2021-32780

Vulnerable Configuration:Configuration 1:
  • cpe:/a:envoyproxy:envoy:1.19.0:*:*:*:*:*:*:*
  • OR cpe:/a:envoyproxy:envoy:*:*:*:*:*:*:*:* (Version >= 1.18.0 and < 1.18.4)

    • Configuration CCN 1:
  • cpe:/a:envoyproxy:envoy:1.19.0:*:*:*:*:*:*:*
  • OR cpe:/a:envoyproxy:envoy:1.18.3:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    envoyproxy envoy 1.19.0
    envoyproxy envoy *
    envoyproxy envoy 1.19.0
    envoyproxy envoy 1.18.3