CVE - CVE-2020-25685

CVE-ID
CVE-2020-25685	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
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.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
DEBIAN:DSA-4844 URL:https://www.debian.org/security/2021/dsa-4844 FEDORA:FEDORA-2021-2e4c3d5a9d URL:https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/ FEDORA:FEDORA-2021-84440e87ba URL:https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/ GENTOO:GLSA-202101-17 URL:https://security.gentoo.org/glsa/202101-17 MISC:https://bugzilla.redhat.com/show_bug.cgi?id=1889688 URL:https://bugzilla.redhat.com/show_bug.cgi?id=1889688 MISC:https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61 URL:https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61 MISC:https://www.jsof-tech.com/disclosures/dnspooq/ URL:https://www.jsof-tech.com/disclosures/dnspooq/
Assigning CNA
Red Hat, Inc.
Date Record Created
20200916	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20200916)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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