CVE-2020-25686
This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq.
Does this matter?
Lower severity and a low EPSS score (4.87%). Track it; it rarely justifies an emergency change on its own.
Description
A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the "Birthday Attacks" section of RFC5452. 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.
- CVSS 3.1
- 3.7 LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 4.87% probability · 92th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-358, CWE-290
- Affected
- thekelleys/dnsmasq · fedoraproject/fedora · debian/debian linux · arista/eos
- Source
- secalert@redhat.com
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1890125Issue Tracking, Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
- https://security.gentoo.org/glsa/202101-17Third Party Advisory
- https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61Third 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=1890125Issue Tracking, Patch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/
- https://security.gentoo.org/glsa/202101-17Third Party Advisory
- https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61Third Party Advisory
- https://www.debian.org/security/2021/dsa-4844Third Party Advisory
- https://www.jsof-tech.com/disclosures/dnspooq/Third Party Advisory
- https://www.kb.cert.org/vuls/id/434904
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.