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.
CVE-2020-1938
“—” 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.
Also known asEUVD-2020-0481 (ENISA EUVD)Source: ENISA EUVD
- 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
A fix is available — apply it.
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.
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
- 99EG 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
Advisory Details (8)
Auto-updated Oct 28, 2026Pony Mail
https://lists.apache.org/thread.html/r4afa11e0464408e68f0e9560e90b185749363a66398b1491254f7864%40%3Cusers.tomcat.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r47caef01f663106c2bb81d116b8380d62beac9e543dd3f3bc2c2beda%40%3Ccommits.tomee.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r43faacf64570b1d9a4bada407a5af3b2738b0c007b905f1b6b608c65%40%3Cusers.tomcat.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r38a5b7943b9a62ecb853acc22ef08ff586a7b3c66e08f949f0396ab1%40%3Cusers.tomcat.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r17aaa3a05b5b7fe9075613dd0c681efa60a4f8c8fbad152c61371b6e%40%3Cusers.tomcat.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r1125f3044a0946d1e7e6f125a6170b58d413ebd4a95157e4608041c7%40%3Cannounce.apache.org%3EPony Mail
https://lists.apache.org/thread.html/r089dc67c0358a1556dd279c762c74f32d7a254a54836b7ee2d839d8e%40%3Cdev.tomee.apache.org%3EBlackBerry Public Knowledge Base
http://support.blackberry.com/kb/articleDetail?articleNumber=000062739Vendor Advisories for CVE-2020-1938(16)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2021:3140Red Hat Product SecurityMedium
Red Hat Security Advisory: Red Hat Fuse 7.9.0 release and security update
- RHSA-2020:4847Red Hat Product SecurityMedium
Red Hat Security Advisory: pki-core:10.6 and pki-deps:10.6 security, bug fix, and enhancement update
- RHSA-2020:2840Red Hat Product SecurityHigh
Red Hat Security Advisory: tomcat security update
- RHSA-2020:2783Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 6.4.23 security update
- RHSA-2020:2779Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 6.4.23 security update
- RHSA-2020:2781Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 6.4.23 security update
- RHSA-2020:2780Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 6.4.23 security update
- RHSA-2020:2367Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat support for Spring Boot 2.1.13 security and bug fix update
- +8 more
Patch Availability(13)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | tomcat | 2021-08-11 | redhat |
| redhat | pki-deps:10.6-8030020200527165326.30b713e6 | 2020-11-04 | redhat |
| redhat | tomcat-0:7.0.76-10.el7_6 | 2020-07-07 | redhat |
| redhat | jbossweb | 2020-07-01 | redhat |
| redhat | weld-core-0:1.1.34-2.Final_redhat_2.1.ep6.el5 | 2020-07-01 | redhat |
| redhat | weld-core-0:1.1.34-2.Final_redhat_2.1.ep6.el6 | 2020-07-01 | redhat |
| redhat | weld-core-0:1.1.34-2.Final_redhat_2.1.ep6.el7 | 2020-07-01 | redhat |
| redhat | ajp | 2020-04-21 | redhat |
| redhat | jws5-tomcat-native-0:1.2.23-4.redhat_4.el8jws | 2020-04-21 | redhat |
| redhat | jbossweb-0:7.5.30-2.Final_redhat_2.1.ep6.el7 | 2020-04-14 | redhat |
| redhat | tomcat6-0:6.0.24-114.el6_10 | 2020-03-23 | redhat |
| redhat | tomcat-0:7.0.76-11.el7_7 | 2020-03-17 | redhat |
| redhat | tomcat-native-0:1.2.23-21.redhat_21.ep7.el7 | 2020-03-17 | redhat |
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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat7 | 7.0.56-3 ... 7.0.56-3+really7.0.99-1 (18 versions) |
| — |
| tomcat8 | 8.0.14-1 ... 8.0.14-1+deb8u9 (17 versions) |
| — |
Debian:10(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | 9.0.16-4 ... 9.0.31-1~bpo10+1 (6 versions) |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | — |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat9 | — |
| — |
Debian:9(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| tomcat8 | 8.5.14-1 ... 8.5.50-0+deb9u1 (37 versions) |
| — |
Maven(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| org.apache.tomcat.embed:tomcat-embed-core | 7.0.0 ... 7.0.99 (68 versions) |
| — |
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.
- 2026-10-31 20:07 UTCEG score recompute
- 2026-10-31 20:07 UTCVendor advisory
- 2026-10-30 17:48 UTCEG score recompute
- 2026-10-30 17:48 UTCVendor advisory
- 2026-10-29 15:31 UTCEG score recompute
- 2026-10-29 15:31 UTCVendor advisory
- 2026-10-28 13:13 UTCEG score recompute
- 2026-10-28 13:13 UTCVendor advisory
- 2026-10-27 10:54 UTCEG score recompute
- 2026-10-27 10:54 UTCVendor advisory
- 2026-10-26 16:27 UTCEPSS rescoreEPSS 99% · 99th percentile
- 2026-10-26 08:37 UTCVendor advisory
- 2026-10-25 18:48 UTCEG score recompute
- 2026-10-25 16:28 UTCEPSS rescoreEPSS 99% · 99th percentile
- 2026-10-25 06:19 UTCEG score recompute
- 2026-10-25 06:19 UTCVendor advisory
- 2026-10-24 04:01 UTCEG score recompute
- 2026-10-24 04:01 UTCVendor advisory
- 2026-10-23 01:42 UTCEG score recompute
- 2026-10-23 01:42 UTCVendor advisory
- 2026-10-21 23:23 UTCEG score recompute
- 2026-10-21 23:23 UTCVendor advisory
- 2026-10-20 21:04 UTCEG score recompute
- 2026-10-20 21:04 UTCVendor advisory
- 2026-10-19 18:46 UTCEG score recompute
Show 75 moreShow fewer
- 2026-10-19 18:46 UTCVendor advisory
- 2026-10-18 16:27 UTCVendor advisory
- 2026-10-18 09:30 UTCEG score recompute
- 2026-10-17 18:53 UTCEG score recompute
- 2026-10-17 18:53 UTCVendor advisory
- 2026-10-17 16:28 UTCEPSS rescoreEPSS 99% · 99th percentile
- 2026-10-16 16:35 UTCEG score recompute
- 2026-10-16 16:35 UTCVendor advisory
- 2026-10-15 14:11 UTCEG score recompute
- 2026-10-15 14:11 UTCVendor advisory
- 2026-10-14 11:51 UTCEG score recompute
- 2026-10-14 11:51 UTCVendor advisory
- 2026-10-13 09:33 UTCVendor advisory
- 2026-10-12 19:43 UTCEG score recompute
- 2026-10-12 07:14 UTCVendor advisory
- 2026-10-12 03:02 UTCVendor advisory
- 2026-10-11 22:49 UTCEG score recompute
- 2026-10-11 22:49 UTCVendor advisory
- 2026-10-11 18:38 UTCEG score recompute
- 2026-10-11 18:38 UTCVendor advisory
- 2026-10-11 14:28 UTCEG score recompute
- 2026-10-11 14:28 UTCVendor advisory
- 2026-10-11 10:17 UTCVendor advisory
- 2026-10-11 06:07 UTCVendor advisory
- 2026-10-11 01:56 UTCVendor advisory
- 2026-10-10 21:44 UTCVendor advisory
- 2026-10-10 17:31 UTCVendor advisory
- 2026-10-10 13:21 UTCVendor advisory
- 2026-10-10 09:10 UTCVendor advisory
- 2026-10-10 05:00 UTCVendor advisory
- 2026-10-10 00:49 UTCVendor advisory
- 2026-10-09 20:38 UTCVendor advisory
- 2026-10-09 16:28 UTCVendor advisory
- 2026-10-09 12:17 UTCVendor advisory
- 2026-10-09 08:06 UTCVendor advisory
- 2026-10-09 03:56 UTCVendor advisory
- 2026-10-08 23:44 UTCVendor advisory
- 2026-10-08 19:34 UTCVendor advisory
- 2026-10-08 15:23 UTCVendor advisory
- 2026-10-08 11:13 UTCVendor advisory
- 2026-10-08 07:03 UTCVendor advisory
- 2026-10-08 02:52 UTCVendor advisory
- 2026-10-07 22:41 UTCVendor advisory
- 2026-10-07 18:30 UTCVendor advisory
- 2026-10-07 14:19 UTCVendor advisory
- 2026-10-07 10:08 UTCVendor advisory
- 2026-10-07 05:58 UTCVendor advisory
- 2026-10-07 01:47 UTCVendor advisory
- 2026-10-06 21:36 UTCVendor advisory
- 2026-10-06 17:26 UTCVendor advisory
- 2026-10-06 13:16 UTCVendor advisory
- 2026-10-06 09:06 UTCVendor advisory
- 2026-10-06 04:56 UTCVendor advisory
- 2026-10-06 00:46 UTCVendor advisory
- 2026-10-05 20:35 UTCVendor advisory
- 2026-10-05 16:25 UTCVendor advisory
- 2026-10-05 12:15 UTCVendor advisory
- 2026-10-05 08:04 UTCVendor advisory
- 2026-10-05 03:53 UTCVendor advisory
- 2026-10-04 23:43 UTCVendor advisory
- 2026-10-04 19:32 UTCVendor advisory
- 2026-10-04 15:22 UTCVendor advisory
- 2026-10-04 11:11 UTCVendor advisory
- 2026-10-04 07:01 UTCVendor advisory
- 2026-10-04 02:51 UTCVendor advisory
- 2026-10-03 22:40 UTCVendor advisory
- 2026-10-03 18:29 UTCVendor advisory
- 2026-10-03 14:16 UTCVendor advisory
- 2026-10-03 10:06 UTCVendor advisory
- 2026-10-03 05:56 UTCVendor advisory
- 2026-10-03 01:45 UTCVendor advisory
- 2026-10-02 21:34 UTCVendor advisory
- 2026-10-02 17:24 UTCVendor advisory
- 2026-10-02 13:11 UTCVendor advisory
- 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✓ verifiedPublished Nov 30, 2020
Apache Tomcat AJP File Read
Open source ↗ - Exploit-DBEDB-49039✓ verifiedPublished Nov 13, 2020
Apache Tomcat - AJP 'Ghostcat' File Read/Inclusion (Metasploit)
Open source ↗ - GitHub checkerlizhianyuguangming/TomcatScanProPublished 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/AttackTomcatPublished 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.yamlPublished Jul 2, 2021
Ghostcat - Apache Tomcat - AJP File Read/Inclusion Vulnerability
Open source ↗ - Open source ↗GitHub PoCHancheng-Lei/Hacking-Vulnerability-CVE-2020-1938-GhostcatPublished Mar 28, 2021
- GitHub PoC00theway/Ghostcat-CNVD-2020-10487Published Feb 22, 2020
Ghostcat read file/code execute,CNVD-2020-10487(CVE-2020-1938)
Open source ↗ - GitHub checkerwoaiqiukui/CVE-2020-1938TomcatAjpScannerPublished Feb 21, 2020
批量扫描TomcatAJP漏洞
Open source ↗ - GitHub PoCfairyming/CVE-2020-1938Published Feb 21, 2020
在一定条件下可执行命令
Open source ↗ - GitHub PoClaolisafe/CVE-2020-1938Published Feb 21, 2020
CVE-2020-1938漏洞复现
Open source ↗
Related CVEs(same product + same vendor)
Same product
10 shownDebian:9:tomcat8
- CVE-2020-9484NVD 7.0EG 7.9EPSS p99HIGH
- CVE-2019-17563EG 7.5EPSS p96HIGH
- CVE-2019-12418EG 7.0HIGH
- CVE-2020-1935EG 4.8EPSS p95MEDIUM
- CVE-2019-17569EG 4.8EPSS p95MEDIUM
- CVE-2019-0221NVD 6.1EG 7.6EPSS p99HIGH
- CVE-2021-25122EG 7.5EPSS p97HIGH
- CVE-2020-11996EG 7.5EPSS p98HIGH
- CVE-2021-25329EG 7.0EPSS p95HIGH
- CVE-2020-13935NVD 7.5EG 9.0EPSS p100CRITICAL
Same vendor
10 shownredhat:RHSA-2020:1520 · redhat:RHSA-2020:0860 · redhat:RHSA-2020:2779
- CVE-2020-1935EG 4.8EPSS p95MEDIUM
- CVE-2019-17563EG 7.5EPSS p96HIGH
- CVE-2019-12418EG 7.0HIGH
- CVE-2019-14885EG 4.3MEDIUM
- CVE-2019-0221NVD 6.1EG 7.6EPSS p99HIGH
- CVE-2019-17569EG 4.8EPSS p95MEDIUM
- CVE-2020-17510EG 9.8EPSS p95CRITICAL
- CVE-2017-5645EG 9.8EPSS p100CRITICAL
- CVE-2019-14887EG 9.1CRITICAL
- CVE-2019-20445EG 9.1EPSS p97CRITICAL
Frequently asked(6)
What is CVE-2020-1938?
When was the CVE record for CVE-2020-1938 published?
Is CVE-2020-1938 actively exploited?
What is the CVSS score of CVE-2020-1938?
Which products are affected by CVE-2020-1938?
How do I remediate CVE-2020-1938?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-1938
Is Your Infrastructure Affected by CVE-2020-1938?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.