CVE-2020-8617

HIGHNVD 7.59.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because EPSS predicts 93% probability of exploitation within the next 30 days (top 0.2% of all CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, ghsa, nvd
Trending — 4 sources updated this weekWeaponized
7.5
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 93%
CISA-KEV: Not listedEPSS: 93%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

Using a specially-crafted message, an attacker may potentially cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG key used by the server. Since BIND, by default, configures a local session key even on servers whose configuration does not otherwise make use of it, almost all current BIND servers are vulnerable. In releases of BIND dating from March 2018 and after, an assertion check in tsig.c detects this inconsistent state and deliberately exits. Prior to the introduction of the check the server would continue operating in an inconsistent state, with potentially harmful results.

CVSS v3
7.5
EG Score
9.0(high)
EG Risk
—
EPSS
99.8%
KEV
Not listed

Published

May 19, 2020

Last Modified

November 21, 2024

References (24)

Patch Availability(14)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntubind9-host (1:9.9.5.dfsg-3ubuntu0.19+esm2) @ trusty2026-05-23ubuntu
ubuntudnsutils (1:9.16.1-0ubuntu2.1) @ focal2026-05-23ubuntu
redhatbind-32:9.9.4-29.el7_2.92020-08-18redhat
redhatbind-32:9.9.4-74.el7_6.42020-08-18redhat
redhatbind-32:9.9.4-50.el7_3.42020-08-18redhat
redhatbind-32:9.9.4-51.el7_4.42020-08-12redhat
redhatbind-32:9.8.2-0.23.rc1.el6_5.92020-08-10redhat
redhatbind-32:9.8.2-0.30.rc1.el6_6.112020-08-10redhat
redhatbind-32:9.11.4-9.P2.el7_7.12020-07-13redhat
redhatbind-32:9.11.4-19.P2.el8_02020-06-04redhat
redhatbind-32:9.8.2-0.68.rc1.el6_10.72020-06-03redhat
redhatbind-32:9.11.4-16.P2.el7_8.62020-06-01redhat
redhatbind-32:9.11.4-26.P2.el8_1.32020-06-01redhat
redhatbind-32:9.11.13-5.el8_22020-05-28redhat

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.

Weakness Classification(1)

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

All Vendor Advisories

(14)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 4× in last 7d / 18× 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.

  1. 2026-07-22 21:29 UTCEG score recompute▲ 3.10
  2. 2026-07-22 21:29 UTCVendor advisory
  3. 2026-07-22 21:29 UTCGHSA enrichment
  4. 2026-07-22 14:05 UTCEPSS rescore
  5. 2026-07-15 16:55 UTCEPSS rescore
  6. 2026-07-15 16:55 UTCEPSS rescore
  7. 2026-07-12 21:07 UTCOSV refresh
  8. 2026-07-06 16:25 UTCEPSS rescore
  9. 2026-07-06 02:21 UTCEPSS rescore
  10. 2026-07-06 02:21 UTCEPSS rescore
  11. 2026-06-30 23:20 UTCEPSS rescore
  12. 2026-06-30 23:20 UTCEPSS rescore
  13. 2026-06-28 14:05 UTCEPSS rescore
  14. 2026-06-27 03:06 UTCEPSS rescore
  15. 2026-06-27 03:06 UTCEPSS rescore
  16. 2026-06-24 06:50 UTCOSV refresh
  17. 2026-06-23 21:31 UTCEPSS rescore
  18. 2026-06-23 21:31 UTCEPSS rescore
  19. 2026-06-21 14:54 UTCEPSS rescore
  20. 2026-06-21 14:54 UTCEPSS rescore
  21. 2026-06-19 19:24 UTCEPSS rescore
  22. 2026-06-19 19:24 UTCEPSS rescore
  23. 2026-06-15 17:46 UTCEPSS rescore
  24. 2026-06-13 22:58 UTCEPSS rescore
  25. 2026-06-13 22:58 UTCEPSS rescore
Show 20 more
  1. 2026-06-10 13:20 UTCEPSS rescore
  2. 2026-06-07 10:29 UTCOSV refresh
  3. 2026-06-05 22:45 UTCEPSS rescore
  4. 2026-06-05 22:45 UTCEPSS rescore
  5. 2026-06-04 13:10 UTCEPSS rescore
  6. 2026-06-04 13:10 UTCEPSS rescore
  7. 2026-06-02 20:11 UTCEPSS rescore
  8. 2026-06-02 20:11 UTCEPSS rescore
  9. 2026-05-31 00:15 UTCEPSS rescore
  10. 2026-05-31 00:15 UTCEPSS rescore
  11. 2026-05-29 13:42 UTCEPSS rescore
  12. 2026-05-28 13:43 UTCEPSS rescore
  13. 2026-05-28 13:43 UTCEPSS rescore
  14. 2026-05-27 13:39 UTCEPSS rescore
  15. 2026-05-27 13:39 UTCEPSS rescore
  16. 2026-05-26 07:17 UTCEPSS rescore
  17. 2026-05-26 07:17 UTCEPSS rescore
  18. 2026-05-23 03:39 UTCEG score recompute
  19. 2026-05-23 03:39 UTCVendor advisory
  20. 2026-05-23 03:39 UTCGHSA enrichment

Publicly available exploits

(3 references)

Working exploit code is in the public domain (1 Metasploit module) (1 GitHub PoC) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-48521
    First seen May 20, 2020

    BIND - 'TSIG' Denial of Service

    Open source ↗
  • GitHub PoCknqyf263/CVE-2020-8617
    First seen May 20, 2020

    PoC for CVE-2020-8617 (BIND)

    Open source ↗
  • Metasploitauxiliary/dos/dns/bind_tsig_badtime✓ verified
    First seen May 19, 2020

    BIND TSIG Badtime Query Denial of Service

    Open source ↗

Frequently asked(5)

What is CVE-2020-8617?
CVE-2020-8617 is a high vulnerability published on May 19, 2020. Using a specially-crafted message, an attacker may potentially cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG key used by the server. Since BIND, by default, configures a local session key even on servers whose configuration…
When was CVE-2020-8617 disclosed?
CVE-2020-8617 was first published in the National Vulnerability Database on May 19, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-8617 actively exploited?
CVE-2020-8617 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2020-8617?
CVE-2020-8617 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
How do I remediate CVE-2020-8617?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-8617, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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