CVE-2019-16779: Excon Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-q58g-455p-8vw9
Share
CVSS 5.8
CWE-362 CWE-664
Published
Advisory Summary

CVE-2019-16779 is a MODERATE (CVSS 5.8) security vulnerability vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Excon libraries in the RubyGems ecosystem. The issue involves in rubygem excon, interrupted persistent connections may leak response data. Remediation is available by upgrading affected packages to version 0.71.0.

CVE-2019-16779 at a Glance

CVE Identifier CVE-2019-16779
GHSA Identifier GHSA-q58g-455p-8vw9
Severity MODERATE
CVSS v3.1 Base Score 5.8
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Product Excon
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 5.8

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

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

How to Fix CVE-2019-16779

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

excon fixed: 0.71.0 
Upgrade excon to 0.71.0
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 excon

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-16779, inspect your project dependencies for Excon:

inspect dependencies for excon

Analyze the terminal output to locate any version of Excon in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.71.0), 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-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. In Excon, 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

### Impact There was a race condition around persistent connections, where a connection which is interrupted (such as by a timeout) would leave data on the socket. Subsequent requests would then read this data, returning content from the previous response. The race condition window appears to be short, and it would be difficult to purposefully exploit this. ### Patches The problem has been patched in 0.71.0, users should upgrade to this or a newer version (if one exists). ### Workarounds Users can workaround the problem by disabling persistent connections, though this may cause performance implications. ### References See the [patch](https://github.com/excon/excon/commit/ccb57d7a422f020dc74f1de4e8fb505ab46d8a29) for further details. ### For more information If you have any questions or comments about this advisory: * Open an issue in [excon/issues](https://github.com/excon/excon/issues) * Email us at [geemus+github@gmail.com](mailto:geemus+github@gmail.com)

CVE-2019-16779 Affected Excon Versions

1 component(s)
Fixed Versions:
0.71.0
Product / Package Ecosystem Affected Versions Fixed Version
excon
gem/excon
RubyGems
< 0.71.0
0.71.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/excon/excon/security/advisories/GHSA-q58g-455p-8vw9
NVD — CVE-2019-16779 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-16779
Security Fix Commit FIX COMMIT
https://github.com/excon/excon/commit/ccb57d7a422f020dc74f1de4e8fb505ab46d8a29
Excon Source Repository REPOSITORY
https://github.com/excon/excon
Excon Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/excon/CVE-2019-16779.yml
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2020/01/msg00015.html
Excon Security Information SECURITY
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00021.html
Excon Security Information SECURITY
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00062.html

Frequently Asked Questions

What is CVE-2019-16779?
CVE-2019-16779 is a security vulnerability in Excon involving In RubyGem excon, interrupted Persistent Connections May Leak Response Data under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Excon versions are affected?
Affected versions include releases prior to 0.71.0 across affected packages: excon.
What version fixes CVE-2019-16779?
Upgrading to 0.71.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is excon affected?
Yes, excon is affected in releases prior to 0.71.0. Upgrade your dependency to 0.71.0 or later.
What is the CVSS score of CVE-2019-16779?
CVE-2019-16779 has a CVSS v3.1 base score of 5.8 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N.
What CWE is associated with CVE-2019-16779?
CVE-2019-16779 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check RubyGems dependencies for CVE-2019-16779?
Run the dependency tree command: 'inspect dependencies for excon'. 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-q58g-455p-8vw9",
  "modified" : "2021-10-29T14:10:27Z",
  "published" : "2019-12-16T19:30:17Z",
  "aliases" : [ "CVE-2019-16779" ],
  "summary" : "In RubyGem excon, interrupted Persistent Connections May Leak Response Data",
  "details" : "### Impact\nThere was a race condition around persistent connections, where a connection which is interrupted (such as by a timeout) would leave data on the socket. Subsequent requests would then read this data, returning content from the previous response. The race condition window appears to be short, and it would be difficult to purposefully exploit this.\n\n### Patches\nThe problem has been patched in 0.71.0, users should upgrade to this or a newer version (if one exists).\n\n### Workarounds\nUsers can workaround the problem by disabling persistent connections, though this may cause performance implications.\n\n### References\nSee the [patch](https://github.com/excon/excon/commit/ccb57d7a422f020dc74f1de4e8fb505ab46d8a29) for further details.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [excon/issues](https://github.com/excon/excon/issues)\n* Email us at [geemus+github@gmail.com](mailto:geemus+github@gmail.com)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "excon"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.71.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/excon/excon/security/advisories/GHSA-q58g-455p-8vw9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-16779"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/excon/excon/commit/ccb57d7a422f020dc74f1de4e8fb505ab46d8a29"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/excon/excon"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/excon/CVE-2019-16779.yml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2020/01/msg00015.html"
  }, {
    "type" : "WEB",
    "url" : "http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00021.html"
  }, {
    "type" : "WEB",
    "url" : "http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00062.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362", "CWE-664" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2019-12-16T19:28:10Z",
    "nvd_published_at" : "2019-12-16T20:15:00Z"
  }
}