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NVD / CVE Program· CNA redhat

CVE-2020-25686: A flaw was found in dnsmasq before version 2.83.

Noroxi assessment

Priority: Monitor (action score 16/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 5.4% (FIRST EPSS); higher than 92.7% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: dnsmasq (Alpine:v3.10) 2.83-r0; dnsmasq (Debian:10) 2.80-1+deb10u1; dnsmasq (Debian:12) 2.83-1.
  • Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to dnsmasq (Alpine:v3.10) 2.83-r0; dnsmasq (Debian:10) 2.80-1+deb10u1; dnsmasq (Debian:12) 2.83-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

LowCVSS 3.7 · v3.1—Proof of concept Fix available
Published
Jan 20, 2021
Updated
Jun 16, 2026
EPSS
5.4% · 92th percentile

Report tools

JSON

Action score

16

Monitor

Low priority for now.

CVSS
14 / 40 · 3.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
2 / 30 · 5.4%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
thekelleysdnsmasq
fedoraprojectfedora
debiandebian linux
aristaeos

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • arista eos4.25 and later · before 4.25.2f
  • arista eos4.21 and later · before 4.21.14m
  • arista eos4.22 and later · before 4.22.9m
  • arista eos4.23 and later · before 4.23.7m
  • arista eos4.24 and later · before 4.24.5m
  • debian debian linux10.0
  • fedoraproject fedora32
  • fedoraproject fedora33
  • thekelleys dnsmasqbefore 2.83

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a dnsmasq

    • dnsmasq 2.83affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.10dnsmasqbefore 2.83-r02.83-r0
Debian:10dnsmasqbefore 2.80-1+deb10u12.80-1+deb10u1
Debian:12dnsmasqbefore 2.83-12.83-1
openSUSE:Leap 15.1dnsmasqbefore 2.78-lp151.5.6.12.78-lp151.5.6.1
openSUSE:Leap 15.2dnsmasqbefore 2.78-lp152.7.3.12.78-lp152.7.3.1
openSUSE:Tumbleweeddnsmasqbefore 2.86-1.12.86-1.1
Red Hat:enterprise_linux:7::clientdnsmasqbefore 0:2.76-16.el7_9.10:2.76-16.el7_9.1
Red Hat:enterprise_linux:7::clientdnsmasq-debuginfobefore 0:2.76-16.el7_9.10:2.76-16.el7_9.1
Red Hat:enterprise_linux:7::clientdnsmasq-utilsbefore 0:2.76-16.el7_9.10:2.76-16.el7_9.1
Red Hat:enterprise_linux:7::hypervisorredhat-virtualization-hostbefore 0:4.3.13-20210127.0.el7_90:4.3.13-20210127.0.el7_9
Red Hat:enterprise_linux:7::hypervisorredhat-virtualization-host-image-updatebefore 0:4.3.13-20210127.0.el7_90:4.3.13-20210127.0.el7_9
Red Hat:enterprise_linux:8::appstreamdnsmasqbefore 0:2.79-13.el8_3.10:2.79-13.el8_3.1
Red Hat:enterprise_linux:8::appstreamdnsmasq-debuginfobefore 0:2.79-13.el8_3.10:2.79-13.el8_3.1
Red Hat:enterprise_linux:8::appstreamdnsmasq-debugsourcebefore 0:2.79-13.el8_3.10:2.79-13.el8_3.1
Red Hat:enterprise_linux:8::appstreamdnsmasq-utilsbefore 0:2.79-13.el8_3.10:2.79-13.el8_3.1
Red Hat:enterprise_linux:8::appstreamdnsmasq-utils-debuginfobefore 0:2.79-13.el8_3.10:2.79-13.el8_3.1
Red Hat:rhel_aus:7.2::serverdnsmasqbefore 0:2.66-14.el7_2.30:2.66-14.el7_2.3
Red Hat:rhel_aus:7.2::serverdnsmasq-debuginfobefore 0:2.66-14.el7_2.30:2.66-14.el7_2.3
Red Hat:rhel_aus:7.2::serverdnsmasq-utilsbefore 0:2.66-14.el7_2.30:2.66-14.el7_2.3
Red Hat:rhel_aus:7.3::serverdnsmasqbefore 0:2.66-21.el7_3.30:2.66-21.el7_3.3
Red Hat:rhel_aus:7.3::serverdnsmasq-debuginfobefore 0:2.66-21.el7_3.30:2.66-21.el7_3.3
Red Hat:rhel_aus:7.3::serverdnsmasq-utilsbefore 0:2.66-21.el7_3.30:2.66-21.el7_3.3
Red Hat:rhel_aus:7.4::serverdnsmasqbefore 0:2.76-2.el7_4.30:2.76-2.el7_4.3
Red Hat:rhel_aus:7.4::serverdnsmasq-debuginfobefore 0:2.76-2.el7_4.30:2.76-2.el7_4.3

+24

Same product

thekelleys: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-14491Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via
    65This week
  • CVE-2020-25681A flaw was found in dnsmasq before version 2.83.
    57Plan
  • CVE-2020-25682A flaw was found in dnsmasq before 2.83.
    55Plan

Published before and after this one in the same product

  • ← EarlierCVE-2020-25684Jan 20, 2021 · A flaw was found in dnsmasq before version 2.83.
    15Monitor
  • ← EarlierCVE-2020-25685Jan 20, 2021 · A flaw was found in dnsmasq before version 2.83.
    15Monitor
  • Later →CVE-2020-25687Jan 20, 2021 · A flaw was found in dnsmasq before version 2.83.
    50Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:dnsmasq2.83-r0 · Alpine:v3.10Package registry (OSV)
debian:dnsmasq2.83-1 · Debian:12Package registry (OSV)
opensuse:dnsmasq2.78-lp152.7.3.1 · openSUSE:Leap 15.2Package registry (OSV)
red hat:dnsmasq0:2.79-13.el8_3.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:dnsmasq-debuginfo0:2.79-13.el8_3.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:dnsmasq-debugsource0:2.79-13.el8_3.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:dnsmasq-utils0:2.79-13.el8_3.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:dnsmasq-utils-debuginfo0:2.79-13.el8_3.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:redhat-virtualization-host0:4.3.13-20210127.0.el7_9 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
red hat:redhat-virtualization-host-image-update0:4.3.13-20210127.0.el7_9 · Red Hat:enterprise_linux:7::hypervisorPackage registry (OSV)
suse:dnsmasq2.78-3.11.1 · SUSE:Linux Enterprise High Performance Computing 15-ESPOSPackage registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:1012021-01-23

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+2 d
  3. TodayOct 31, 2026+2110 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-358 · Improperly Implemented Security Check for Standard

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records