Vulnerability Monitor

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CVE-2020-25686


A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the "Birthday Attacks" section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.


Security Impact Summary

This vulnerability carries a LOW severity rating with a CVSS v3.1 score of 3.7, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts limited integrity, for affected systems. Impacting 4 products from thekelleys, from fedoraproject, from debian and 1 other, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-01-20T17:15:13.000

Last Modified

2025-11-04T20:15:57.490

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 3.7 (LOW)

CVSSv2 Vector

AV:N/AC:M/Au:N/C:N/I:P/A:N

  • Access Vector: NETWORK
  • Access Complexity: MEDIUM
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: PARTIAL
  • Availability Impact: NONE
Exploitability Score

8.6

Impact Score

2.9

Weaknesses
  • Type: Secondary
    CWE-358
  • Type: Secondary
    CWE-290

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application thekelleys dnsmasq < 2.83 Yes
Operating System fedoraproject fedora 32 Yes
Operating System fedoraproject fedora 33 Yes
Operating System debian debian_linux 10.0 Yes
Operating System arista eos < 4.21.14m Yes
Operating System arista eos < 4.22.9m Yes
Operating System arista eos < 4.23.7m Yes
Operating System arista eos < 4.24.5m Yes
Operating System arista eos < 4.25.2f Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For thekelleys's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.