Cyber Resilience

CVE-2023-3635

Squareup Okio 0.5.0 – 1.17.6

Public PoC
Published
12 July 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 5.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.013 67th percentile
Risk Priority 48 floored blend · peak EPSS

Summary

CVE-2023-3635 is a medium-severity Signed to Unsigned Conversion Error (CWE-195) vulnerability in Squareup Okio. Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 33% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability Data

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.

CWE(s)
CWE-195CWE-681

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-45799Same vendor: Squareup
CVE-2023-28063Shared CWE-195, CWE-681
CVE-2023-5184Shared CWE-195, CWE-681
CVE-2023-20006Shared CWE-681
CVE-2024-7747Shared CWE-681
CVE-2026-24174Shared CWE-681
CVE-2024-1552Shared CWE-681
CVE-2026-4931Shared CWE-681
CVE-2026-4602Shared CWE-681
CVE-2023-3782Same vendor: Squareup

Affected Assets

squareup
okio
0.5.0 — 1.17.6 · 2.0.0 — 3.4.0

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe-integer standards) directly prevent signed-to-unsigned conversion errors.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect conversion-related defects before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates practices that can catch signed-to-unsigned conversion errors during design and coding.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify safe integer handling and type-conversion rules.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure system architecture and engineering principles include data-type safety and overflow prevention.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prohibit unsafe signed-to-unsigned casts and require defensive checks.

References