CVE-2020-1938

CRITICALNVD 9.89.8
EchelonGraph scoreHIGH confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2022-03-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: CISA Known Exploited Vulnerabilities catalog, EPSS, NVD CVSS v3
Trending — 3 sources updated this weekExploited in the wild

Also known asEUVD-2020-0481 (ENISA EUVD)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • 107 internet-facing services (distinct ip:port) on record running an affected version — derived from Shodan data (© Shodan); a patched service can stay counted while its port stays open
  • Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low mission impact
CISA-KEV: ExploitedEPSS PROB: 99%CVSS: 9.8Exploit: Metasploit · Exploit-DB (verified) · other public PoCExposed services: 107

A fix is available — apply it.

When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP connections as having higher trust than, for example, a similar HTTP connection. If such connections are available to an attacker, they can be exploited in ways that may be surprising. In Apache Tomcat 9.0.0.M1 to 9.0.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99, Tomcat shipped with an AJP Connector enabled by default that listened on all configured IP addresses. It was expected (and recommended in the security guide) that this Connector would be disabled if not required. This vulnerability report identified a mechanism that allowed: - returning arbitrary files from anywhere in the web application - processing any file in the web application as a JSP Further, if the web application allowed file upload and stored those files within the web application (or the attacker was able to control the content of the web application by some other means) then this, along with the ability to process a file as a JSP, made remote code execution possible. It is important to note that mitigation is only required if an AJP port is accessible to untrusted users. Users wishing to take a defence-in-depth approach and block the vector that permits returning arbitrary files and execution as JSP may upgrade to Apache Tomcat 9.0.31, 8.5.51 or 7.0.100 or later. A number of changes were made to the default AJP Connector configuration in 9.0.31 to harden the default configuration. It is likely that users upgrading to 9.0.31, 8.5.51 or 7.0.100 or later will need to make small changes to their configurations.

Internet exposure · derived from Shodan data

107 internet-facing services (distinct ip:port) on record running a version that maps to CVE-2020-1938, in our KEV-Exposure radar’s Shodan-derived sample.

across 27 countries (China, United States, Germany, Korea, Republic of, Brazil)top: tomcat
See the KEV-Exposure radar →Derived from Shodan data. Shodan data is owned by Shodan, which holds its copyright (© Shodan). EchelonGraph claims no ownership of it or copyright in it. Aggregate, host-redacted.

How it counts: every 12 hours, when Shodan query credits allow, the radar runs one Shodan query per tracked product, reads up to 100 ip:port services per query, and keeps a service when its banner version matches a CISA-KEV or high-EPSS CVE; a service is dropped when neither a search nor a Shodan InternetDB port re-check has refreshed it for 21 days. A re-check that finds the port still listed by Shodan InternetDB refreshes the service without re-reading the banner, so a patched service can stay counted while its port stays open. A count is a banner-version inference over a sample, not an exploit test and not an internet-wide census, and the unit is a service, not a machine: a machine answering on two ports counts twice.

CVSS v3
9.8
EG Score
9.8CRITICALhigh confidence
EG Risk
99
EG Risk 99/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation100% × 40%
Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Attend at low mission impact; Act at medium or high.
Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it sooner than your standard update timelines at low mission impact and as soon as possible at medium or high.
EPSS PROB
99%
EPSS %ILE
99th
KEV
⚠ Exploited

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
99% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Act at medium mission impactAttend at low mission impact; Act at medium or high.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Attend at low mission impact; Act at medium or high.

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

Exploitation active (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days & forensic triage if the affected system is publicly exposed; 3 days & forensic triage if it is not.

In CISA KEV yes (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

CISA required action“Apply updates per vendor instructions.”

Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://nvd.nist.gov/vuln/detail/CVE-2020-1938

Published

February 24, 2020

Last Modified

August 25, 2026

Patch Availability(13)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhattomcat2021-08-11redhat
redhatpki-deps:10.6-8030020200527165326.30b713e62020-11-04redhat
redhattomcat-0:7.0.76-10.el7_62020-07-07redhat
redhatjbossweb2020-07-01redhat
redhatweld-core-0:1.1.34-2.Final_redhat_2.1.ep6.el52020-07-01redhat
redhatweld-core-0:1.1.34-2.Final_redhat_2.1.ep6.el62020-07-01redhat
redhatweld-core-0:1.1.34-2.Final_redhat_2.1.ep6.el72020-07-01redhat
redhatajp2020-04-21redhat
redhatjws5-tomcat-native-0:1.2.23-4.redhat_4.el8jws2020-04-21redhat
redhatjbossweb-0:7.5.30-2.Final_redhat_2.1.ep6.el72020-04-14redhat
redhattomcat6-0:6.0.24-114.el6_102020-03-23redhat
redhattomcat-0:7.0.76-11.el7_72020-03-17redhat
redhattomcat-native-0:1.2.23-21.redhat_21.ep7.el72020-03-17redhat

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

(9 across 8 ecosystems)
Debian:8(2)
PackageVulnerable rangeFix by version rangeDependents
tomcat77.0.56-3 ... 7.0.56-3+really7.0.99-1 (18 versions)
  • every version up to 7.0.56-3+really7.0.100-1: fixed in 7.0.56-3+really7.0.100-1
—
tomcat88.0.14-1 ... 8.0.14-1+deb8u9 (17 versions)
  • every version up to 8.0.14-1+deb8u17: fixed in 8.0.14-1+deb8u17
—
Debian:10(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat99.0.16-4 ... 9.0.31-1~bpo10+1 (6 versions)
  • every version up to 9.0.31-1~deb10u1: fixed in 9.0.31-1~deb10u1
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat9—
  • every version up to 9.0.31-1: fixed in 9.0.31-1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat9—
  • every version up to 9.0.31-1: fixed in 9.0.31-1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat9—
  • every version up to 9.0.31-1: fixed in 9.0.31-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat9—
  • every version up to 9.0.31-1: fixed in 9.0.31-1
—
Debian:9(1)
PackageVulnerable rangeFix by version rangeDependents
tomcat88.5.14-1 ... 8.5.50-0+deb9u1 (37 versions)
  • every version up to 8.5.54-0+deb9u1: fixed in 8.5.54-0+deb9u1
—
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
org.apache.tomcat.embed:tomcat-embed-core7.0.0 ... 7.0.99 (68 versions)
  • 9.0.0 up to 9.0.31: fixed in 9.0.31
  • 8.0.0 up to 8.5.51: fixed in 8.5.51
  • 7.0.0 up to 7.0.100: fixed in 7.0.100
—

Data Freshness Timeline

(refreshed 16× in last 7d / 102× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 892 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 792 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-31 20:07 UTCEG score recompute
  2. 2026-10-31 20:07 UTCVendor advisory
  3. 2026-10-30 17:48 UTCEG score recompute
  4. 2026-10-30 17:48 UTCVendor advisory
  5. 2026-10-29 15:31 UTCEG score recompute
  6. 2026-10-29 15:31 UTCVendor advisory
  7. 2026-10-28 13:13 UTCEG score recompute
  8. 2026-10-28 13:13 UTCVendor advisory
  9. 2026-10-27 10:54 UTCEG score recompute
  10. 2026-10-27 10:54 UTCVendor advisory
  11. 2026-10-26 16:27 UTCEPSS rescoreEPSS 99% · 99th percentile
  12. 2026-10-26 08:37 UTCVendor advisory
  13. 2026-10-25 18:48 UTCEG score recompute
  14. 2026-10-25 16:28 UTCEPSS rescoreEPSS 99% · 99th percentile
  15. 2026-10-25 06:19 UTCEG score recompute
  16. 2026-10-25 06:19 UTCVendor advisory
  17. 2026-10-24 04:01 UTCEG score recompute
  18. 2026-10-24 04:01 UTCVendor advisory
  19. 2026-10-23 01:42 UTCEG score recompute
  20. 2026-10-23 01:42 UTCVendor advisory
  21. 2026-10-21 23:23 UTCEG score recompute
  22. 2026-10-21 23:23 UTCVendor advisory
  23. 2026-10-20 21:04 UTCEG score recompute
  24. 2026-10-20 21:04 UTCVendor advisory
  25. 2026-10-19 18:46 UTCEG score recompute
Show 75 more
  1. 2026-10-19 18:46 UTCVendor advisory
  2. 2026-10-18 16:27 UTCVendor advisory
  3. 2026-10-18 09:30 UTCEG score recompute
  4. 2026-10-17 18:53 UTCEG score recompute
  5. 2026-10-17 18:53 UTCVendor advisory
  6. 2026-10-17 16:28 UTCEPSS rescoreEPSS 99% · 99th percentile
  7. 2026-10-16 16:35 UTCEG score recompute
  8. 2026-10-16 16:35 UTCVendor advisory
  9. 2026-10-15 14:11 UTCEG score recompute
  10. 2026-10-15 14:11 UTCVendor advisory
  11. 2026-10-14 11:51 UTCEG score recompute
  12. 2026-10-14 11:51 UTCVendor advisory
  13. 2026-10-13 09:33 UTCVendor advisory
  14. 2026-10-12 19:43 UTCEG score recompute
  15. 2026-10-12 07:14 UTCVendor advisory
  16. 2026-10-12 03:02 UTCVendor advisory
  17. 2026-10-11 22:49 UTCEG score recompute
  18. 2026-10-11 22:49 UTCVendor advisory
  19. 2026-10-11 18:38 UTCEG score recompute
  20. 2026-10-11 18:38 UTCVendor advisory
  21. 2026-10-11 14:28 UTCEG score recompute
  22. 2026-10-11 14:28 UTCVendor advisory
  23. 2026-10-11 10:17 UTCVendor advisory
  24. 2026-10-11 06:07 UTCVendor advisory
  25. 2026-10-11 01:56 UTCVendor advisory
  26. 2026-10-10 21:44 UTCVendor advisory
  27. 2026-10-10 17:31 UTCVendor advisory
  28. 2026-10-10 13:21 UTCVendor advisory
  29. 2026-10-10 09:10 UTCVendor advisory
  30. 2026-10-10 05:00 UTCVendor advisory
  31. 2026-10-10 00:49 UTCVendor advisory
  32. 2026-10-09 20:38 UTCVendor advisory
  33. 2026-10-09 16:28 UTCVendor advisory
  34. 2026-10-09 12:17 UTCVendor advisory
  35. 2026-10-09 08:06 UTCVendor advisory
  36. 2026-10-09 03:56 UTCVendor advisory
  37. 2026-10-08 23:44 UTCVendor advisory
  38. 2026-10-08 19:34 UTCVendor advisory
  39. 2026-10-08 15:23 UTCVendor advisory
  40. 2026-10-08 11:13 UTCVendor advisory
  41. 2026-10-08 07:03 UTCVendor advisory
  42. 2026-10-08 02:52 UTCVendor advisory
  43. 2026-10-07 22:41 UTCVendor advisory
  44. 2026-10-07 18:30 UTCVendor advisory
  45. 2026-10-07 14:19 UTCVendor advisory
  46. 2026-10-07 10:08 UTCVendor advisory
  47. 2026-10-07 05:58 UTCVendor advisory
  48. 2026-10-07 01:47 UTCVendor advisory
  49. 2026-10-06 21:36 UTCVendor advisory
  50. 2026-10-06 17:26 UTCVendor advisory
  51. 2026-10-06 13:16 UTCVendor advisory
  52. 2026-10-06 09:06 UTCVendor advisory
  53. 2026-10-06 04:56 UTCVendor advisory
  54. 2026-10-06 00:46 UTCVendor advisory
  55. 2026-10-05 20:35 UTCVendor advisory
  56. 2026-10-05 16:25 UTCVendor advisory
  57. 2026-10-05 12:15 UTCVendor advisory
  58. 2026-10-05 08:04 UTCVendor advisory
  59. 2026-10-05 03:53 UTCVendor advisory
  60. 2026-10-04 23:43 UTCVendor advisory
  61. 2026-10-04 19:32 UTCVendor advisory
  62. 2026-10-04 15:22 UTCVendor advisory
  63. 2026-10-04 11:11 UTCVendor advisory
  64. 2026-10-04 07:01 UTCVendor advisory
  65. 2026-10-04 02:51 UTCVendor advisory
  66. 2026-10-03 22:40 UTCVendor advisory
  67. 2026-10-03 18:29 UTCVendor advisory
  68. 2026-10-03 14:16 UTCVendor advisory
  69. 2026-10-03 10:06 UTCVendor advisory
  70. 2026-10-03 05:56 UTCVendor advisory
  71. 2026-10-03 01:45 UTCVendor advisory
  72. 2026-10-02 21:34 UTCVendor advisory
  73. 2026-10-02 17:24 UTCVendor advisory
  74. 2026-10-02 13:11 UTCVendor advisory
  75. 2026-10-02 09:00 UTCVendor advisory

Publicly available exploits

(14 references, 10 shown)

Public exploit code is referenced for this CVE (1 Metasploit module, 2 Exploit-DB entries, 7 GitHub PoCs), as are 1 Nuclei detection template, 3 GitHub checker repositories. A detection template checks whether a system is affected; it is not necessarily exploit code. A GitHub repository named or described as a checker or scanner checks whether a system is affected; it is not necessarily exploit code. Defenders should treat patch urgency accordingly.

  • Metasploitauxiliary/admin/http/tomcat_ghostcat✓ verified
    Published Nov 30, 2020

    Apache Tomcat AJP File Read

    Open source ↗
  • Exploit-DBEDB-49039✓ verified
    Published Nov 13, 2020

    Apache Tomcat - AJP 'Ghostcat' File Read/Inclusion (Metasploit)

    Open source ↗
  • GitHub checkerlizhianyuguangming/TomcatScanPro
    Published Aug 29, 2024

    tomcat自动化漏洞扫描利用工具,支持批量弱口令检测、后台部署war包getshell、CVE-2017-12615 文件上传、CVE-2020-1938/CNVD-2020-10487 文件包含

    Open source ↗
  • GitHub PoCtpt11fb/AttackTomcat
    Published Nov 13, 2022

    Tomcat常见漏洞GUI利用工具。CVE-2017-12615 PUT文件上传漏洞、tomcat-pass-getshell 弱认证部署war包、弱口令爆破、CVE-2020-1938 Tomcat AJP文件读取/包含

    Open source ↗
  • Nucleinetwork/cves/2020/CVE-2020-1938.yaml
    Published Jul 2, 2021

    Ghostcat - Apache Tomcat - AJP File Read/Inclusion Vulnerability

    Open source ↗
  • GitHub PoCHancheng-Lei/Hacking-Vulnerability-CVE-2020-1938-Ghostcat
    Published Mar 28, 2021
    Open source ↗
  • GitHub PoC00theway/Ghostcat-CNVD-2020-10487
    Published Feb 22, 2020

    Ghostcat read file/code execute,CNVD-2020-10487(CVE-2020-1938)

    Open source ↗
  • GitHub checkerwoaiqiukui/CVE-2020-1938TomcatAjpScanner
    Published Feb 21, 2020

    批量扫描TomcatAJP漏洞

    Open source ↗
  • GitHub PoCfairyming/CVE-2020-1938
    Published Feb 21, 2020

    在一定条件下可执行命令

    Open source ↗
  • GitHub PoClaolisafe/CVE-2020-1938
    Published Feb 21, 2020

    CVE-2020-1938漏洞复现

    Open source ↗

Frequently asked(6)

What is CVE-2020-1938?
CVE-2020-1938 is a critical-severity vulnerability; its CVE record was published on February 24, 2020. When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP connections as having higher trust than, for example, a similar HTTP connection. If such connections are available to an attacker, they can be exploited in ways that…
When was the CVE record for CVE-2020-1938 published?
The CVE record for CVE-2020-1938 was published on February 24, 2020. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 25, 2026; the record at its source may have been updated since.
Is CVE-2020-1938 actively exploited?
Yes. CISA added CVE-2020-1938 to the Known Exploited Vulnerabilities catalog on March 3, 2022, affecting Apache Tomcat. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate attention. A fix is available. Apply it.
What is the CVSS score of CVE-2020-1938?
CVE-2020-1938 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2020-1938?
CVE-2020-1938 affects Apache Tomcat. The affected packages EchelonGraph has on record, with version ranges, are listed in the Affected Packages section of this page.
How do I remediate CVE-2020-1938?
A fix for CVE-2020-1938 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2020-1938 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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