In Apache Tomcat there is an improper handing of overflow in the UTF-8 decoder

Description

An improper handing of overflow in the UTF-8 decoder with supplementary characters can lead to an infinite loop in the decoder causing a Denial of Service. Versions Affected: Apache Tomcat 9.0.0.M9 to 9.0.7, 8.5.0 to 8.5.30, 8.0.0.RC1 to 8.0.51, and 7.0.28 to 7.0.86.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
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Repository advisory
Source code
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Published (advisory)
2018-10-17 16:32:18 UTC
Updated
2024-02-23 17:57:10 UTC
GitHub reviewed
2020-06-16 21:44:57 UTC
NVD published
2018-08-02

EPSS Score

Score Percentile
18.55% 95.21%

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:N/I:N/A:H 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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

CWEs

CWE id Name
CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')

Credits

  • sunSUNQ (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, < 8.5.31 8.5.31
maven org.apache.tomcat.embed:tomcat-embed-core >= 7.0.28, < 7.0.87 7.0.87
maven org.apache.tomcat.embed:tomcat-embed-core >= 9.0.0.M9, <= 9.0.7 9.0.8
maven org.apache.tomcat.embed:tomcat-embed-core >= 8.0.0RC1, < 8.0.51 8.0.51

References

cvelogic Threat Intelligence