CVE-2021-39162: Github.com/pomerium/pomerium Incorrect Handling Of H2 GOAWAY Vulnerability

HIGH
Advisory Identifier: GHSA-gjcg-vrxg-xmgv
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CVSS 8.6
CWE-754
Published
Advisory Summary

CVE-2021-39162 is a HIGH (CVSS 8.6) incorrect handling of h2 goaway vulnerability (CWE-754: Improper Check for Unusual or Exceptional Conditions) affecting Github.com/pomerium/pomerium libraries in the Go ecosystem. The issue involves incorrect handling of h2 goaway + settings frames. Remediation is available by upgrading affected packages to version 0.15.1.

CVE-2021-39162 at a Glance

CVE Identifier CVE-2021-39162
GHSA Identifier GHSA-gjcg-vrxg-xmgv
Severity HIGH
CVSS v3.1 Base Score 8.6
CWE Classification CWE-754: Improper Check for Unusual or Exceptional Conditions
Affected Product Github.com/pomerium/pomerium
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 8.6

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:C/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 Changed (S:C)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2021-39162

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

github.com/pomerium/pomerium fixed: 0.15.1 
Upgrade github.com/pomerium/pomerium to 0.15.1
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 github.com/pomerium/pomerium

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-39162, inspect your project dependencies for Github.com/pomerium/pomerium:

inspect dependencies for github.com/pomerium/pomerium

Analyze the terminal output to locate any version of Github.com/pomerium/pomerium in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.15.1), 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-754: Improper Check for Unusual or Exceptional Conditions, where the product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product. In Github.com/pomerium/pomerium, 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

Envoy, which Pomerium is based on, can abnormally terminate if an H/2 GOAWAY and SETTINGS frame are received in the same IO event. ### Impact This can lead to a DoS in the presence of untrusted *upstream* servers. ### Patches 0.15.1 contains an upgraded envoy binary with this vulnerability patched. ### Workarounds If only trusted upstreams are configured, there is not substantial risk of this condition being triggered. ### References [envoy GSA](https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8) [envoy CVE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-32780) [envoy announcement](https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJ) ### For more information If you have any questions or comments about this advisory: * Open an issue in [pomerium/pomerium](https://github.com/pomerium/pomerium/issues) * Email us at [security@pomerium.com](mailto:security@pomerium.com)

CVE-2021-39162 Affected Github.com/pomerium/pomerium Versions

1 component(s)
Fixed Versions:
0.15.1
Product / Package Ecosystem Affected Versions Fixed Version
github.com/pomerium/pomerium
golang/github.com/pomerium/pomerium
Go
< 0.15.1
0.15.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8
GitHub Advisory / Wiki ADVISORY
https://github.com/pomerium/pomerium/security/advisories/GHSA-gjcg-vrxg-xmgv
NVD — CVE-2021-39162 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-39162
Github.com/pomerium/pomerium Source Repository REPOSITORY
https://github.com/pomerium/pomerium
groups.google.com/g/envoy-announce/c/... WEB
https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJ

Frequently Asked Questions

What is CVE-2021-39162?
CVE-2021-39162 is a security vulnerability in Github.com/pomerium/pomerium involving Incorrect handling of H2 GOAWAY + SETTINGS frames under CWE-754: Improper Check for Unusual or Exceptional Conditions.
Which Github.com/pomerium/pomerium versions are affected?
Affected versions include releases prior to 0.15.1 across affected packages: github.com/pomerium/pomerium.
What version fixes CVE-2021-39162?
Upgrading to 0.15.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/pomerium/pomerium affected?
Yes, github.com/pomerium/pomerium is affected in releases prior to 0.15.1. Upgrade your dependency to 0.15.1 or later.
What is the CVSS score of CVE-2021-39162?
CVE-2021-39162 has a CVSS v3.1 base score of 8.6 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
What CWE is associated with CVE-2021-39162?
CVE-2021-39162 is classified under CWE-754: Improper Check for Unusual or Exceptional Conditions (The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.).
How can I check Go dependencies for CVE-2021-39162?
Run the dependency tree command: 'inspect dependencies for github.com/pomerium/pomerium'. 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-gjcg-vrxg-xmgv",
  "modified" : "2021-09-10T16:32:16Z",
  "published" : "2021-09-10T17:54:01Z",
  "aliases" : [ "CVE-2021-39162" ],
  "summary" : "Incorrect handling of H2 GOAWAY + SETTINGS frames",
  "details" : "Envoy, which Pomerium is based on, can abnormally terminate if an H/2 GOAWAY and SETTINGS frame are received in the same IO event.  \n\n### Impact\nThis can lead to a DoS in the presence of untrusted *upstream* servers.\n\n### Patches\n0.15.1 contains an upgraded envoy binary with this vulnerability patched.\n\n### Workarounds\nIf only trusted upstreams are configured, there is not substantial risk of this condition being triggered.\n\n### References\n[envoy GSA](https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8)\n[envoy CVE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-32780)\n[envoy announcement](https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJ)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [pomerium/pomerium](https://github.com/pomerium/pomerium/issues)\n* Email us at [security@pomerium.com](mailto:security@pomerium.com)\n\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/pomerium/pomerium"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.15.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pomerium/pomerium/security/advisories/GHSA-gjcg-vrxg-xmgv"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-39162"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pomerium/pomerium"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJ"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-754" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-09-10T16:32:16Z",
    "nvd_published_at" : "2021-09-09T22:15:00Z"
  }
}