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.
CVE-2020-11767
This low-severity CVE scores 3.1 under NVD CVSS v3. EPSS exploit probability: 1.8%, top 24% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 3.1
- EG Score
- 3.1(medium)
- EG Risk
- 19(Track)EG Risk 19/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity31% × 45%Exploitation2% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 2%
- EPSS %ILE
- 76%
- KEV
- Not listed
Published
April 15, 2020
Last Modified
November 21, 2024
References (8)
- cve@mitrehttps://bugs.chromium.org/p/chromium/issues/detail?id=954160#c5
- cve@mitrehttps://github.com/envoyproxy/envoy/issues/6767
- cve@mitrehttps://github.com/istio/istio/issues/13589
- cve@mitrehttps://github.com/istio/istio/issues/9429
- af854a3a-2127-422b-91ae-364da2661108https://bugs.chromium.org/p/chromium/issues/detail?id=954160#c5
- af854a3a-2127-422b-91ae-364da2661108https://github.com/envoyproxy/envoy/issues/6767
- af854a3a-2127-422b-91ae-364da2661108https://github.com/istio/istio/issues/13589
- af854a3a-2127-422b-91ae-364da2661108https://github.com/istio/istio/issues/9429
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 31× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 129 total refreshes for this CVE.
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Frequently asked(5)
What is CVE-2020-11767?
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What is the CVSS score of CVE-2020-11767?
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2020-11767
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