CVE-2023-3782Public exploitNetwork attack vector

Client process crash via unbounded Brotli decompression

Published Jul 19, 2023 · Updated Oct 28, 2024

Uncontrolled resource consumption in Block, Inc. OkHttp Brotli allows remote attackers to crash a client via a malicious HTTP response. The BrotliInterceptor.intercept() path automatically decompresses a Brotli-encoded body without limiting its expansion, allowing kilobytes to consume gigabytes of memory. The interceptor must be enabled, and reachability requires a malicious server or a man-in-the-middle attacker able to inject the response.

CVSS severity5.9
Medium
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Block, Inc. OkHttp Brotli allows remote attackers to crash a client via a malicious HTTP response. The BrotliInterceptor.intercept() path automatically decompresses a Brotli-encoded body without limiting its expansion, allowing kilobytes to consume gigabytes of memory. The interceptor must be enabled, and reachability requires a malicious server or a man-in-the-middle attacker able to inject the response.

The record

CVE
CVE-2023-3782
Published
Jul 19, 2023
Updated
Oct 28, 2024
Vendor
Block, Inc.
Product
OkHttp Brotli
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <*

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Block, Inc. · OkHttp Brotliversion=0 <*

Published CVSS scores

5.9JFrogCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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