CVE-2020-25687 | Date: (C)2021-01-21 (M)2023-12-22 |
A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. This flaw allows a remote attacker, who can create valid DNS replies, to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in sort_rrset() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
CVSS Score and Metrics +CVSS Score and Metrics -CVSS V3 Severity: | CVSS V2 Severity: |
CVSS Score : 5.9 | CVSS Score : 7.1 |
Exploit Score: 2.2 | Exploit Score: 8.6 |
Impact Score: 3.6 | Impact Score: 6.9 |
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CVSS V3 Metrics: | CVSS V2 Metrics: |
Attack Vector: NETWORK | Access Vector: NETWORK |
Attack Complexity: HIGH | Access Complexity: MEDIUM |
Privileges Required: NONE | Authentication: NONE |
User Interaction: NONE | Confidentiality: NONE |
Scope: UNCHANGED | Integrity: NONE |
Confidentiality: NONE | Availability: COMPLETE |
Integrity: NONE | |
Availability: HIGH | |
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