CVE-2020-11767Public exploitNetwork attack vector

Cross-domain data disclosure via HTTP/2 connection reuse

Published Apr 15, 2020 · Updated Aug 4, 2024

Information disclosure in Istio 1.5.1 and earlier and Envoy 1.14.1 and earlier allows remote attackers to receive cross-domain HTTPS data. Their HTTP/2 routing path accepts a reused TLS connection for a different origin instead of returning 421 Misdirected Request. Exposure requires a shared forward proxy, connection reuse, and overlapping wildcard and explicit SNI hosts; only misrouted request data is disclosed.

CVSS severity3.1
Low
EPSS probability1.82%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Istio 1.5.1 and earlier and Envoy 1.14.1 and earlier allows remote attackers to receive cross-domain HTTPS data. Their HTTP/2 routing path accepts a reused TLS connection for a different origin instead of returning 421 Misdirected Request. Exposure requires a shared forward proxy, connection reuse, and overlapping wildcard and explicit SNI hosts; only misrouted request data is disclosed.

The record

CVE
CVE-2020-11767
Published
Apr 15, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-200, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

3.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
2.6NIST NVDAV:N/AC:H/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1557Adversary-in-the-Middle

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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