Vulnerability in Envoyproxy Envoy
CVE-2020-11767
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.018 (77.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: +0.000
Affected products
References
- bugs.chromium.org/p/chromium/issues/detail (Third Party Advisory, Issue Tracking)
- github.com/envoyproxy/envoy/issues/6767 (Third Party Advisory)
- github.com/istio/istio/issues/9429 (Third Party Advisory)
- github.com/istio/istio/issues/13589 (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-11767?
- CVE-2020-11767 is a low-severity vulnerability in Envoyproxy Envoy. CVSS score: 3.1/10. Published 2020-04-15.
- How severe is CVE-2020-11767?
- Low severity. CVSS v3 base score is 3.1 out of 10.