CVE-2020-25685: arista eos Inadequate Encryption Strength

Vulnerability summary

CVE-2020-25685 is a medium (CVSS 4.3) Inadequate Encryption Strength vulnerability in arista eos. EPSS estimates a 2.18% chance of exploitation in the next 30 days, higher than 82% of scored vulnerabilities.

Timeline

1. 20-01-2021
   PublishedVulnerability first disclosed.
2. 04-11-2025
   Last modifiedVulnerability information updated.

Description

A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. 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.

• CWE-326Inadequate Encryption StrengthThe product stores or transmits sensitive data using an encryption scheme that is theoretically sound, but is not strong enough for the level of protection required.