CVE-2021-3448A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses…
- 4.0MediumCVSS base score
- 2.3%Exploitation in 30 daysEPSS · top 17% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest threat from this vulnerability is to data integrity.
Timeline
ID reserved
By redhat
- 23 days later
· 23 days later
Published
- 5 years later
· 5 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Medium4.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N |
| NVDNVD · Modified | 3.1 | Medium4.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 2.3% · top 17% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.0.
Affected products
dnsmasq
- affected dnsmasq 2.85
References
References6
- https://bugzilla.redhat.com/show_bug.cgi?id=1939368 (opens in a new tab)x_refsource_MISCx_transferred
- FEDORA-2021-62a5062b2d (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2021-9433bedebd (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2021-5cd2571751 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- GLSA-202105-20 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- https://www.oracle.com/security-alerts/cpujan2022.html (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-26773 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-3448)Record last updated .