CVE-2018-20994: Trust dns proto Uncontrolled Recursion Vulnerability

HIGH
Advisory Identifier: GHSA-369h-pjr2-6wrh
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CVSS 7.5
CWE-674
Published
Advisory Summary

CVE-2018-20994 is a HIGH (CVSS 7.5) uncontrolled recursion vulnerability (CWE-674: Uncontrolled Recursion) affecting Trust dns proto libraries in the crates.io ecosystem. The issue involves uncontrolled recursion in trust-dns-proto. Remediation is available by upgrading affected packages to version 0.4.3.

CVE-2018-20994 at a Glance

CVE Identifier CVE-2018-20994
GHSA Identifier GHSA-369h-pjr2-6wrh
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-674: Uncontrolled Recursion
Affected Product Trust dns proto
Package Ecosystem crates.io
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:3.0/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-2018-20994

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

trust-dns-proto fixed: 0.4.3 
Upgrade trust-dns-proto to 0.4.3
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 trust-dns-proto

How to Check if You Are Affected

To determine whether your application is affected by CVE-2018-20994, inspect your project dependencies for Trust dns proto:

inspect dependencies for trust-dns-proto

Analyze the terminal output to locate any version of Trust dns proto in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.4.3), 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-674: Uncontrolled Recursion, where the product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. In Trust dns proto, 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

There's a stack overflow leading to a crash when Trust-DNS's parses a malicious DNS packet. Affected versions of this crate did not properly handle parsing of DNS message compression (RFC1035 section 4.1.4). The parser could be tricked into infinite loop when a compression offset pointed back to the same domain name to be parsed. This allows an attacker to craft a malicious DNS packet which when consumed with Trust-DNS could cause stack overflow and crash the affected software.

CVE-2018-20994 Affected Trust dns proto Versions

1 component(s)
Fixed Versions:
0.4.3
Product / Package Ecosystem Affected Versions Fixed Version
trust-dns-proto
 crates.io
< 0.4.3
0.4.3

References

NVD — CVE-2018-20994 NVD
https://nvd.nist.gov/vuln/detail/CVE-2018-20994
Trust dns proto Source Repository REPOSITORY
https://github.com/bluejekyll/trust-dns
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2018-0007.html

Frequently Asked Questions

What is CVE-2018-20994?
CVE-2018-20994 is a security vulnerability in Trust dns proto involving Uncontrolled recursion in trust-dns-proto under CWE-674: Uncontrolled Recursion.
Which Trust dns proto versions are affected?
Affected versions include releases prior to 0.4.3 across affected packages: trust-dns-proto.
What version fixes CVE-2018-20994?
Upgrading to 0.4.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is trust-dns-proto affected?
Yes, trust-dns-proto is affected in releases prior to 0.4.3. Upgrade your dependency to 0.4.3 or later.
What is the CVSS score of CVE-2018-20994?
CVE-2018-20994 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2018-20994?
CVE-2018-20994 is classified under CWE-674: Uncontrolled Recursion (The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.).
How can I check crates.io dependencies for CVE-2018-20994?
Run the dependency tree command: 'inspect dependencies for trust-dns-proto'. 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-369h-pjr2-6wrh",
  "modified" : "2023-06-13T22:25:06Z",
  "published" : "2021-08-25T20:43:16Z",
  "aliases" : [ "CVE-2018-20994" ],
  "summary" : "Uncontrolled recursion in trust-dns-proto",
  "details" : "There's a stack overflow leading to a crash when Trust-DNS's parses a malicious DNS packet. Affected versions of this crate did not properly handle parsing of DNS message compression (RFC1035 section 4.1.4). The parser could be tricked into infinite loop when a compression offset pointed back to the same domain name to be parsed. This allows an attacker to craft a malicious DNS packet which when consumed with Trust-DNS could cause stack overflow and crash the affected software.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "trust-dns-proto"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.4.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2018-20994"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/bluejekyll/trust-dns"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2018-0007.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-674" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T21:24:41Z",
    "nvd_published_at" : null
  }
}