// For flags

CVE-2023-31147

Insufficient randomness in generation of DNS query IDs in c-ares

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

c-ares is an asynchronous resolver library. When /dev/urandom or RtlGenRandom() are unavailable, c-ares uses rand() to generate random numbers used for DNS query ids. This is not a CSPRNG, and it is also not seeded by srand() so will generate predictable output. Input from the random number generator is fed into a non-compilant RC4 implementation and may not be as strong as the original RC4 implementation. No attempt is made to look for modern OS-provided CSPRNGs like arc4random() that is widely available. This issue has been fixed in version 1.19.1.

A vulnerability was found in c-ares. This issue occurs when /dev/urandom or RtlGenRandom() are unavailable, c-ares will use rand() to generate random numbers used for DNS query ids. This is not a CSPRNG, and it is also not seeded by srand(), so it will generate predictable output.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2023-04-24 CVE Reserved
  • 2023-05-25 CVE Published
  • 2024-08-02 CVE Updated
  • 2024-11-04 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-330: Use of Insufficiently Random Values
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
C-ares Project
Search vendor "C-ares Project"
 C-ares
Search vendor "C-ares Project" for product "C-ares"
 < 1.19.1
Search vendor "C-ares Project" for product "C-ares" and version " < 1.19.1"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 37
Search vendor "Fedoraproject" for product "Fedora" and version "37"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 38
Search vendor "Fedoraproject" for product "Fedora" and version "38"
-
Affected