CVE-2020-25685

LOWNVD 3.73.7—
EchelonGraph scoreMEDIUM confidence

Score 3.7 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 3.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
3.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 2.2%CVSS: 3.7Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
3.7
EG Score
3.7LOWmedium confidence
EG Risk
22
EG Risk 22/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity37% × 45%
Exploitation2% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
2.2%
EPSS %ILE
81st
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

January 20, 2021

Last Modified

November 4, 2025

References (15)

Vendor Advisories for CVE-2020-25685(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(12)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntudnsmasq-utils (2.75-1ubuntu0.16.04.7) @ xenial2026-05-26ubuntu
redhatredhat-virtualization-host-0:4.4.4-20210201.0.el8_32021-02-03redhat
redhatredhat-virtualization-host-0:4.3.13-20210127.0.el7_92021-02-03redhat
redhatdnsmasq-0:2.66-14.el7_2.32021-01-25redhat
redhatdnsmasq-0:2.66-21.el7_3.32021-01-25redhat
redhatdnsmasq-0:2.76-10.el7_7.22021-01-19redhat
redhatdnsmasq-0:2.79-13.el8_3.12021-01-19redhat
redhatdnsmasq-0:2.79-11.el8_2.22021-01-19redhat
redhatdnsmasq-0:2.76-2.el7_4.32021-01-19redhat
redhatdnsmasq-0:2.76-7.el7_6.22021-01-19redhat
redhatdnsmasq-0:2.79-6.el8_1.12021-01-19redhat
redhatdnsmasq-0:2.76-16.el7_9.12021-01-19redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(20 across 20 ecosystems)
Alpine:v3.10(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.11(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.12(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.13(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.14(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.15(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.16(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.17(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.18(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.19(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.20(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-r0: fixed in 2.83-r0
—
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq2.80-1
  • every version up to 2.80-1+deb10u1: fixed in 2.80-1+deb10u1
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-1: fixed in 2.83-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-1: fixed in 2.83-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-1: fixed in 2.83-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
dnsmasq—
  • every version up to 2.83-1: fixed in 2.83-1
—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(12)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 6× in last 7d / 29× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 175 total refreshes for this CVE.

  1. 2026-10-09 20:04 UTCEPSS rescore
  2. 2026-10-08 16:38 UTCEPSS rescore
  3. 2026-10-07 23:44 UTCEPSS rescore
  4. 2026-10-06 15:13 UTCEPSS rescore
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  7. 2026-10-03 14:22 UTCEPSS rescore
  8. 2026-10-02 16:22 UTCEPSS rescore
  9. 2026-09-30 15:16 UTCEG score recompute
  10. 2026-09-30 14:59 UTCEPSS rescore
  11. 2026-09-27 13:40 UTCEPSS rescore
  12. 2026-09-26 15:54 UTCEPSS rescore
  13. 2026-09-26 11:55 UTCOSV refresh
  14. 2026-09-26 00:20 UTCEPSS rescore
  15. 2026-09-24 14:00 UTCEPSS rescore
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  17. 2026-09-22 14:43 UTCEPSS rescore
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  20. 2026-09-18 19:23 UTCEPSS rescore
  21. 2026-09-17 19:22 UTCEPSS rescore
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  23. 2026-09-16 14:04 UTCEPSS rescore
  24. 2026-09-15 03:06 UTCEPSS rescore
  25. 2026-09-15 03:06 UTCEPSS rescore
Show 75 more
  1. 2026-09-13 16:42 UTCEPSS rescore
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  3. 2026-09-11 14:48 UTCEPSS rescore
  4. 2026-09-11 09:32 UTCEPSS rescore
  5. 2026-09-10 09:29 UTCEPSS rescore
  6. 2026-09-08 21:56 UTCEPSS rescore
  7. 2026-09-07 15:57 UTCEPSS rescore
  8. 2026-09-06 23:31 UTCOSV refresh
  9. 2026-09-06 13:44 UTCEPSS rescore
  10. 2026-09-05 15:24 UTCEPSS rescore
  11. 2026-09-04 13:57 UTCEPSS rescore
  12. 2026-09-04 05:03 UTCEPSS rescore
  13. 2026-09-02 14:08 UTCEPSS rescore
  14. 2026-09-01 03:32 UTCEPSS rescore
  15. 2026-08-30 19:14 UTCEPSS rescore
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  17. 2026-08-27 14:21 UTCEPSS rescore
  18. 2026-08-26 14:42 UTCEPSS rescore
  19. 2026-08-25 13:45 UTCEPSS rescore
  20. 2026-08-21 23:45 UTCEPSS rescore
  21. 2026-08-20 22:52 UTCEPSS rescore
  22. 2026-08-20 09:31 UTCOSV refresh
  23. 2026-08-19 17:00 UTCEPSS rescore
  24. 2026-08-18 13:44 UTCEPSS rescore
  25. 2026-08-17 13:43 UTCEPSS rescore
  26. 2026-08-16 14:52 UTCEPSS rescore
  27. 2026-08-16 02:11 UTCEPSS rescore
  28. 2026-08-15 01:26 UTCEPSS rescore
  29. 2026-08-13 21:57 UTCEPSS rescore
  30. 2026-08-12 13:47 UTCEPSS rescore
  31. 2026-08-09 13:43 UTCEPSS rescore
  32. 2026-08-08 16:33 UTCEPSS rescore
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  34. 2026-08-06 13:43 UTCEPSS rescore
  35. 2026-08-05 19:14 UTCEPSS rescore
  36. 2026-08-05 04:41 UTCOSV refresh
  37. 2026-08-04 15:06 UTCEPSS rescore
  38. 2026-08-04 10:34 UTCEPSS rescore
  39. 2026-08-03 10:32 UTCEPSS rescore
  40. 2026-08-02 02:23 UTCEPSS rescore
  41. 2026-08-01 04:12 UTCEPSS rescore
  42. 2026-07-30 16:25 UTCEPSS rescore
  43. 2026-07-30 01:27 UTCEPSS rescore
  44. 2026-07-28 15:32 UTCEPSS rescore
  45. 2026-07-26 14:51 UTCEPSS rescore
  46. 2026-07-25 14:15 UTCEPSS rescore
  47. 2026-07-25 14:14 UTCEPSS rescore
  48. 2026-07-24 14:14 UTCEPSS rescore
  49. 2026-07-23 14:15 UTCEPSS rescore
  50. 2026-07-23 14:15 UTCEPSS rescore
  51. 2026-07-23 01:51 UTCEG score recompute
  52. 2026-07-22 22:37 UTCEG score recompute
  53. 2026-07-22 14:05 UTCEPSS rescore
  54. 2026-07-21 15:22 UTCEPSS rescore
  55. 2026-07-21 15:22 UTCEPSS rescore
  56. 2026-07-20 17:04 UTCEPSS rescore
  57. 2026-07-20 17:04 UTCEPSS rescore
  58. 2026-07-19 14:28 UTCEPSS rescore
  59. 2026-07-19 03:22 UTCOSV refresh
  60. 2026-07-19 02:26 UTCEPSS rescore
  61. 2026-07-19 02:26 UTCEPSS rescore
  62. 2026-07-18 10:02 UTCEPSS rescore
  63. 2026-07-16 16:59 UTCEPSS rescore
  64. 2026-07-15 16:55 UTCEPSS rescore
  65. 2026-07-15 01:57 UTCEPSS rescore
  66. 2026-07-13 22:27 UTCEPSS rescore
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  68. 2026-07-13 06:10 UTCEPSS rescore
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  70. 2026-07-12 05:44 UTCEPSS rescore
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  73. 2026-07-09 19:07 UTCEPSS rescore
  74. 2026-07-08 15:12 UTCEPSS rescore
  75. 2026-07-07 13:43 UTCEPSS rescore

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2020-25685?
CVE-2020-25685 is a low vulnerability published on January 20, 2021. 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…
When was CVE-2020-25685 disclosed?
CVE-2020-25685 was first published on January 20, 2021, with the most recent update on November 4, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-25685 actively exploited?
CVE-2020-25685 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.2% probability of exploitation in the next 30 days (81st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-25685?
CVE-2020-25685 has a CVSS v3 base score of 3.7 (NVD).
How do I remediate CVE-2020-25685?
A fix for CVE-2020-25685 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2020-25685 are linked in the Vendor Advisories panel on this page.

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