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Fencer Intel
medium 6.8

CVE-2020-16844 json

Authorization bypass in Istio

published 6y ago modified 4mo ago also GHSA-82mm-ffjr-h86c , EUVD-2022-0899

cvss
6.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits
0
none known

Summary

In Istio 1.5.0 though 1.5.8 and Istio 1.6.0 through 1.6.7, when users specify an AuthorizationPolicy resource with DENY actions using wildcard suffixes (e.g. *-some-suffix) for source principals or namespace fields, callers will never be denied access, bypassing the intended policy.

Patch / fix

  • go istio.io/istio 1.5.9, 1.6.8
  • servicemesh service mesh 1.1 1.1.7-1.el8
  • servicemesh-mixc service mesh 1.1 1.1.7-1.el8
  • servicemesh-mixs service mesh 1.1 1.1.7-1.el8
  • servicemesh-galley service mesh 1.1 1.1.7-1.el8
  • servicemesh-citadel service mesh 1.1 1.1.7-1.el8
  • servicemesh-istioctl service mesh 1.1 1.1.7-1.el8
  • servicemesh-pilot-agent service mesh 1.1 1.1.7-1.el8
  • servicemesh-pilot-discovery service mesh 1.1 1.1.7-1.el8

red hat advisories RHSA-2020:3425

Is CVE-2020-16844 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-16844 updated cvss 6.8

istio: incorrect translation of DENY policy for TCP service

  • Red Hat OpenShift Service Mesh 1.1 servicemesh 1.1.7-1.el8, servicemesh-mixc 1.1.7-1.el8, servicemesh-mixs 1.1.7-1.el8, servicemesh-galley 1.1.7-1.el8, servicemesh-citadel 1.1.7-1.el8, servicemesh-istioctl 1.1.7-1.el8, +3 more
    fixed: vendor fix RHSA-2020:3425

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.10% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • istio.io https://istio.io/latest/news/security/istio-security-2020-009/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
NVD 2.0 4.9 AV:N/AC:M/Au:S/C:P/I:P/A:N
GitHub 3.1 6.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
go istio.io/istio
>=1.5.0, <1.5.9
>=1.6.0, <1.6.8
1.5.9
1.6.8

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.