CVE-2020-25685

CVSS V2 Medium 4.3 CVSS V3 Low 3.7
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.
Overview
  • CVE ID
  • CVE-2020-25685
  • Assigner
  • secalert@redhat.com
  • Vulnerability Status
  • Analyzed
  • Published Version
  • 2021-01-20T16:15:14
  • Last Modified Date
  • 2022-12-08T03:08:50
Weakness Enumerations
CWE URL
CWE-326 http://cwe.mitre.org/data/definitions/326.html
CPE Configuration (Product)
CPE Vulnerable Operator Version Start Version End
cpe:2.3:a:thekelleys:dnsmasq:*:*:*:*:*:*:*:* 1 OR 2.83
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* 1 OR
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 1 OR 4.21 4.21.14m
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 1 OR 4.22 4.22.9m
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 1 OR 4.23 4.23.7m
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 1 OR 4.24 4.24.5m
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:* 1 OR 4.25 4.25.2f
CVSS Version 2
  • Version
  • 2.0
  • Vector String
  • AV:N/AC:M/Au:N/C:N/I:P/A:N
  • Access Vector
  • NETWORK
  • Access Compatibility
  • MEDIUM
  • Authentication
  • NONE
  • Confidentiality Impact
  • NONE
  • Integrity Impact
  • PARTIAL
  • Availability Impact
  • NONE
  • Base Score
  • 4.3
  • Severity
  • MEDIUM
  • Exploitability Score
  • 8.6
  • Impact Score
  • 2.9
CVSS Version 3
  • Version
  • 3.1
  • Vector String
  • CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
  • Attack Vector
  • NETWORK
  • Attack Compatibility
  • HIGH
  • Privileges Required
  • NONE
  • User Interaction
  • NONE
  • Scope
  • UNCHANGED
  • Confidentiality Impact
  • NONE
  • Availability Impact
  • NONE
  • Base Score
  • 3.7
  • Base Severity
  • LOW
  • Exploitability Score
  • 2.2
  • Impact Score
  • 1.4
References
Reference URL Reference Tags
https://www.jsof-tech.com/disclosures/dnspooq/ Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1889688 Issue Tracking Patch Third Party Advisory
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
Sources
Source Name Source URL
NIST https://nvd.nist.gov/vuln/detail/CVE-2020-25685
MITRE https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-25685
History
Created Old Value New Value Data Type Notes
2022-05-10 06:32:49 Added to TrackCVE
2022-12-05 20:34:27 2021-01-20T16:15Z 2021-01-20T16:15:14 CVE Published Date updated
2022-12-05 20:34:27 2022-10-07T14:15:57 CVE Modified Date updated
2022-12-05 20:34:27 Undergoing Analysis Vulnerability Status updated
2022-12-08 03:37:26 2022-12-08T03:08:50 CVE Modified Date updated
2022-12-08 03:37:26 Undergoing Analysis Analyzed Vulnerability Status updated