Vulnerability Name:

CVE-2020-11767 (CCN-180304)

Assigned:2019-05-01
Published:2019-05-01
Updated:2021-07-21
Summary:Istio through 1.5.1 and Envoy through 1.14.1 have a data-leak issue. If there is a TCP connection (negotiated with SNI over HTTPS) to *.example.com, a request for a domain concurrently configured explicitly (e.g., abc.example.com) is sent to the server(s) listening behind *.example.com. The outcome should instead be 421 Misdirected Request. Imagine a shared caching forward proxy re-using an HTTP/2 connection for a large subnet with many users. If a victim is interacting with abc.example.com, and a server (for abc.example.com) recycles the TCP connection to the forward proxy, the victim's browser may suddenly start sending sensitive data to a *.example.com server. This occurs because the forward proxy between the victim and the origin server reuses connections (which obeys the specification), but neither Istio nor Envoy corrects this by sending a 421 error. Similarly, this behavior voids the security model browsers have put in place between domains.
CVSS v3 Severity:3.1 Low (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N)
2.8 Low (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N/E:U/RL:U/RC:R)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): None
Availibility (A): None
7.5 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
6.6 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:U/RC:R)
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): High
Integrity (I): None
Availibility (A): None
CVSS v2 Severity:2.6 Low (CVSS v2 Vector: AV:N/AC:H/Au:N/C:P/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): High
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): None
7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:C/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): Complete
Integrity (I): None
Availibility (A): None
Vulnerability Type:CWE-200
Vulnerability Consequences:Obtain Information
References:Source: MITRE
Type: CNA
CVE-2020-11767

Source: MISC
Type: Issue Tracking, Third Party Advisory
https://bugs.chromium.org/p/chromium/issues/detail?id=954160#c5

Source: XF
Type: UNKNOWN
istio-cve202011767-info-disc(180304)

Source: CCN
Type: Envoy GIT Repository
Envoy does not adhere to HTTP/2 RFC 7540 #6767

Source: MISC
Type: Third Party Advisory
https://github.com/envoyproxy/envoy/issues/6767

Source: CCN
Type: Istio GIT Repository
Istio does not adhere to HTTP/2 RFC 7540 #13589

Source: MISC
Type: Exploit, Third Party Advisory
https://github.com/istio/istio/issues/13589

Source: MISC
Type: Third Party Advisory
https://github.com/istio/istio/issues/9429

Vulnerable Configuration:Configuration 1:
  • cpe:/a:envoyproxy:envoy:*:*:*:*:*:*:*:* (Version <= 1.14.1)
  • OR cpe:/a:istio:istio:*:*:*:*:*:*:*:* (Version <= 1.5.1)

    • * Denotes that component is vulnerable
    BACK
    envoyproxy envoy *
    istio istio *