CVE Vulnerability
CVE-2020-25685
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.
References
| Link | Resource |
|---|---|
| https://www.jsof-tech.com/disclosures/dnspooq/ | Third Party Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=1889688 | Issue Tracking Patch |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/ | Mailing List Third Party Advisory |
| https://security.gentoo.org/glsa/202101-17 | Third Party Advisory |
| https://www.debian.org/security/2021/dsa-4844 | Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/ | Mailing List Third Party Advisory |
| https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61 | Third Party Advisory |
Configurations
Configuration 1
|
Information
Published : 2021-01-20 04:15
Updated : 2022-12-08 03:08
NVD link : CVE-2020-25685
Mitre link : CVE-2020-25685
Products Affected
No products.
CWE
CWE-328
Use of Weak Hash