What is the CVSS score of CVE-2020-16844?

CVE-2020-16844 has a CVSS 3.1 base score of 6.8 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N. EPSS exploitation probability: 1.1%.

Is there a public PoC exploit available for CVE-2020-16844?

Yes, a public proof-of-concept exploit is available for CVE-2020-16844. Prioritise patching immediately. EPSS: 1.1%.

Is there a patch available for CVE-2020-16844?

Yes, a patch is available for CVE-2020-16844. Update the affected software to the latest version immediately.

Istio CVE-2020-16844

MEDIUM

2020-10-01 cve@mitre.org

Authentication Bypass Istio

6.8

CVSS 3.1 · NVD

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Vulnerability Assessment

Impact	CVSS score of 6.8 (MEDIUM). Attack characteristics: network attack vector, high complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available.
Exploit ScenarioDerived	This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the medium-severity affected system.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

Patch available 1.1% exploitation probability (EPSS)

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AnalysisAI

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. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. Public exploit code available and no vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affected Packages

go istio.io/istio fix: 1.5.9, 1.6.8

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in go

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

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. Affected products include: Istio. Version information: through 1.6.7.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 6.8 MEDIUM

AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

DescriptionNVD

Threat Intelligence Overview

EPSS Score

1.1%

Top 38% exploitable

Exploit

POC

Public exploit code exists

Data Quality

3 sources

Confidence: Low

NVD

CVE.org

EPSS

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity MEDIUM

CISA KEV No

Public POC Yes

EPSS 1.1%

Patch available Yes

Active threat No

Deciding rule

MEDIUM severity (CVSS 4.0-6.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Human Impact· derived

Medium

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +1

CVSS: +34

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Authentication Bypass CRITICAL

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

Affected Products (CPE)NVD

cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*

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References

Advisories & patches

ADVISORY https://github.com/istio/istio/releases

Search Externally

GitHub PoC

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