Exposure of Sensitive Information to an Unauthorized Actor in Apache Tomcat

Description

When responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A's request.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Browse source ↗
Published (advisory)
2021-06-16 17:45:29 UTC
Updated
2026-06-05 17:40:10 UTC
GitHub reviewed
2021-03-24 19:53:13 UTC
NVD published
2021-03-01

EPSS Score

Score Percentile
2.77% 86.22%

CVSS Scores

Base score Version Severity Vector
7.5 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

Credits

  • hara-satoshi-ymr (analyst)

Affected packages (4)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
maven org.apache.tomcat.embed:tomcat-embed-core >= 8.5.0, < 8.5.63 8.5.63
maven org.apache.tomcat.embed:tomcat-embed-core >= 10.0.0-M1, < 10.0.2 10.0.2
maven org.apache.tomcat.embed:tomcat-embed-core >= 9.0.0-M1, < 9.0.43 9.0.43
maven org.apache.tomcat:tomcat-coyote >= 10.0.0-M1, < 10.0.2 10.0.2

References

cvelogic Threat Intelligence