CVE-2019-18817: Istio.io/istio Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-vc7h-cmp3-4hw5
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CVSS 7.5
CWE-835
Published
Advisory Summary

CVE-2019-18817 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')) affecting Istio.io/istio libraries in the Go ecosystem. The issue involves istio vulnerable to denial of service. Remediation is available by upgrading affected packages to version 1.3.5.

CVE-2019-18817 at a Glance

CVE Identifier CVE-2019-18817
GHSA Identifier GHSA-vc7h-cmp3-4hw5
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')
Affected Product Istio.io/istio
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2019-18817

To remediate this vulnerability, upgrade all affected Istio.io/istio dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

istio.io/istio fixed: 1.3.5 
Upgrade istio.io/istio to 1.3.5
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for istio.io/istio

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-18817, inspect your project dependencies for Istio.io/istio:

inspect dependencies for istio.io/istio

Analyze the terminal output to locate any version of Istio.io/istio in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.3.5), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop'), where the product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. In Istio.io/istio, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Istio 1.3.x before 1.3.5 is vulnerable to denial of service because `continue_on_listener_filters_timeout` is set to True, a related issue to CVE-2019-18836.

CVE-2019-18817 Affected Istio.io/istio Versions

1 component(s)
Fixed Versions:
1.3.5
Product / Package Ecosystem Affected Versions Fixed Version
istio.io/istio
golang/istio.io/istio
Go
≥ 1.3.0
< 1.3.5
1.3.5

References

NVD — CVE-2019-18817 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-18817
Istio.io/istio Source Repository REPOSITORY
https://github.com/istio/istio/issues/18229
Istio.io/istio Source Repository REPOSITORY
https://github.com/istio/istio/issues/18229#issuecomment-553190142
Security Fix Commit FIX COMMIT
https://github.com/istio/istio/commit/7570a1f5b56c108aed6ecfa5d2a6048f444bfb37
Istio.io/istio Source Repository REPOSITORY
https://github.com/istio/istio
istio.io/news/2019/announcin... WEB
https://istio.io/news/2019/announcing-1.3.5

Frequently Asked Questions

What is CVE-2019-18817?
CVE-2019-18817 is a security vulnerability in Istio.io/istio involving Istio vulnerable to denial of service under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop').
Which Istio.io/istio versions are affected?
Affected versions include releases prior to 1.3.5 across affected packages: istio.io/istio.
What version fixes CVE-2019-18817?
Upgrading to 1.3.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is istio.io/istio affected?
Yes, istio.io/istio is affected in releases prior to 1.3.5. Upgrade your dependency to 1.3.5 or later.
What is the CVSS score of CVE-2019-18817?
CVE-2019-18817 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2019-18817?
CVE-2019-18817 is classified under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') (The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.).
How can I check Go dependencies for CVE-2019-18817?
Run the dependency tree command: 'inspect dependencies for istio.io/istio'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vc7h-cmp3-4hw5",
  "modified" : "2023-10-19T18:09:28Z",
  "published" : "2022-05-24T22:01:14Z",
  "aliases" : [ "CVE-2019-18817" ],
  "summary" : "Istio vulnerable to denial of service",
  "details" : "Istio 1.3.x before 1.3.5 is vulnerable to denial of service because `continue_on_listener_filters_timeout` is set to True, a related issue to CVE-2019-18836.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "istio.io/istio"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.3.0"
      }, {
        "fixed" : "1.3.5"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-18817"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/istio/istio/issues/18229"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/istio/istio/issues/18229#issuecomment-553190142"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/istio/istio/commit/7570a1f5b56c108aed6ecfa5d2a6048f444bfb37"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/istio/istio"
  }, {
    "type" : "WEB",
    "url" : "https://istio.io/news/2019/announcing-1.3.5"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-835" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-10-19T18:09:28Z",
    "nvd_published_at" : "2019-11-12T14:15:00Z"
  }
}