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

Exp

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.

Published: 2023-07-12 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-3635 is rated High Exploit Risk (62.7/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.57%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-3635

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-3635

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-12 0.50% 0.57% +0.07%
2 2026-04-21 0.57% 0.50% -0.07%
3 2026-04-09 — 0.57% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-3635

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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.
 2.2 3.6 [email protected]
7.5 3.1 HIGH
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.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-3635

GitHub Security Advisory for CVE-2023-3635

GHSA-w33c-445m-f8w7 · Severity: medium · Ecosystem: maven — Okio Signed to Unsigned Conversion Error vulnerability

OS Trackers for CVE-2023-3635

vendor priority summary link
debian unimportant CVE-2023-3635 unimportant priority: Debian including 1 source packages (okio), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-3635
redhat high — https://access.redhat.com/security/cve/CVE-2023-3635
ubuntu medium CVE-2023-3635 medium priority: Ubuntu including 1 source packages (okio), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 7, needs-triage 6. https://ubuntu.com/security/CVE-2023-3635

Affected software / configurations for CVE-2023-3635

Vendor Product Version Raw CPE
squareup okio >= 0.5.0, < 1.17.6 cpe:2.3:a:squareup:okio:*:*:*:*:*:*:*:*
squareup okio >= 2.0.0, < 3.4.0 cpe:2.3:a:squareup:okio:*:*:*:*:*:*:*:*

References for CVE-2023-3635

cvelogic Threat Intelligence