What’s Vulnerable › Vulnerabilities

CVE-2023-3635: Okio GzipSource unhandled exception Denial of Service

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-07-12 · updated 2026-06-17
• Weakness: CWE-195

Description

GzipSource does not handle an exception that might be raised when parsing a malformed gzip buffer. This may lead to denial of service of the Okio client when handling a crafted GZIP archive, by using the GzipSource class.

Affected products

• Squareup Okio: from 0.5.0 before 1.17.6; from 2.0.0 before 3.4.0 — fixed in 1.17.6, 3.4.0

How to fix

Upgrade to a fixed version: Squareup Okio 1.17.6, 3.4.0. Check the vendor advisory for mitigations.

References

• https://github.com/square/okio/commit/81bce1a30af244550b0324597720e4799281da7b
• https://research.jfrog.com/vulnerabilities/okio-gzip-source-unhandled-exception-dos-xray-523195/
• https://github.com/square/okio/commit/81bce1a30af244550b0324597720e4799281da7b
• https://research.jfrog.com/vulnerabilities/okio-gzip-source-unhandled-exception-dos-xray-523195/

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