CVE-2021-30640: Auth weakness in JNDIRealm
Vulnerability summary
CVE-2021-30640 is a medium (CVSS 6.5) Improper Encoding or Escaping of Output vulnerability in apache software foundation apache tomcat. EPSS estimates a 9.89% chance of exploitation in the next 30 days, higher than 95.5% of scored vulnerabilities.
Not severe (CVSS 6.5, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 14 · Related 10Timeline
- 12-07-2021PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
A vulnerability in the JNDI Realm of Apache Tomcat allows an attacker to authenticate using variations of a valid user name and/or to bypass some of the protection provided by the LockOut Realm. This issue affects Apache Tomcat 10.0.0-M1 to 10.0.5; 9.0.0.M1 to 9.0.45; 8.5.0 to 8.5.65.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
- OSV · MavenEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
EPSS trend
Probability
9.89%
Chance of exploitation in the next 30 days
Percentile
96%
Versus all other CVEs
30-day change
No change 0.00 pp
From 9.89% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Oracle5 products
- communications_cloud_native_core_policy1.14.0
- communications_diameter_signaling_router≥ 8.0.0, ≤ 8.5.0
- communications_pricing_design_center12.0.0.3.0
- hospitality_cruise_shipboard_property_management_system20.1.0
- tekelec_platform_distribution≥ 7.4.0, ≤ 7.7.1
Ubuntu4 products
- tomcat6All versions (No fix recorded)
- tomcat7All versions (No fix recorded)
- tomcat8All versions (No fix recorded)
- tomcat9< 9.0.16-3ubuntu0.18.04.2 | < 9.0.31-1ubuntu0.2
Debian2 products
- tomcat9< 9.0.43-2
- debian_linuxEOL9.0 | 10.0 | 11.0
Apache1 product
- tomcat≥ 7.0.0, < 7.0.109 | ≥ 8.5.0, < 8.5.66 | ≥ 9.0.0, < 9.0.46 | ≥ 10.0.0, < 10.0.6
Apache software foundation1 product
- apache tomcatApache Tomcat 10 10.0.0-M1 to 10.0.5 | Apache Tomcat 9 9.0.0.M1 to 9.0.45 | Apache Tomcat 8.5 8.5.0 to 8.5.65 | Apache Tomcat 7 7.0.0 to 7.0.108
Org.apache.tomcat1 product
- tomcat≥ 10.0.0-M1, < 10.0.5 | ≥ 9.0.0M1, < 9.0.45 | ≥ 8.5.0, < 8.5.65
6 vendors · 14 products
References
32 links
lists.debian.org/debian-lts-announce/2021/08/msg00009.htmlMailing ListX Refsource MLISTWEBThird Party Advisory
