Vulnerability Description
A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in the forward.c:reply_query() if the reply destination address/port is used by the pending forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query, substantially reducing the number of attempts an attacker on the network would have to perform to forge a reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query's attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.
CVSS Score
LOW
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Thekelleys | Dnsmasq | < 2.83 |
| Fedoraproject | Fedora | 32 |
| Debian | Debian Linux | 9.0 |
| Arista | Eos | >= 4.21, < 4.21.14m |
Related Weaknesses (CWE)
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1889686Issue TrackingPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00027.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202101-17Third Party Advisory
- https://www.arista.com/en/support/advisories-notices/security-advisories/12135-sThird Party Advisory
- https://www.debian.org/security/2021/dsa-4844Third Party Advisory
- https://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1889686Issue TrackingPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00027.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://security.gentoo.org/glsa/202101-17Third Party Advisory
- https://www.arista.com/en/support/advisories-notices/security-advisories/12135-sThird Party Advisory
- https://www.debian.org/security/2021/dsa-4844Third Party Advisory
FAQ
What is CVE-2020-25684?
CVE-2020-25684 is a vulnerability with a CVSS score of 3.7 (LOW). A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in the forward.c:reply_query() if the reply destination address/port is used by the pending...
How severe is CVE-2020-25684?
CVE-2020-25684 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-25684?
Check the references section above for vendor advisories and patch information. Affected products include: Thekelleys Dnsmasq, Fedoraproject Fedora, Debian Debian Linux, Arista Eos.