CVE-2022-39173Public exploitNetwork attack vector

Server crash via duplicate cipher-suite amplification

Published Sep 29, 2022 · Updated May 20, 2025

Buffer overflow in wolfSSL before 5.5.1 allows remote attackers to crash TLS 1.3 servers with crafted Client Hello messages. RefineSuites appends matching peer cipher suites without deduplicating entries or checking its fixed stack-array capacity; a retry processes the expanded list again, multiplying duplicates until the buffer is overwritten. The server must use TLS 1.3 with session tickets enabled, and the client must attempt session resumption while forcing a Hello Retry Request; the confirmed impact is a crash, not code execution.

CVSS severity7.5
High
EPSS probability4.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in wolfSSL before 5.5.1 allows remote attackers to crash TLS 1.3 servers with crafted Client Hello messages. RefineSuites appends matching peer cipher suites without deduplicating entries or checking its fixed stack-array capacity; a retry processes the expanded list again, multiplying duplicates until the buffer is overwritten. The server must use TLS 1.3 with session tickets enabled, and the client must attempt session resumption while forcing a Hello Retry Request; the confirmed impact is a crash, not code execution.

The record

CVE
CVE-2022-39173
Published
Sep 29, 2022
Updated
May 20, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 29, 2022CVE publishedPublication date reported by the CVE source.
  2. May 20, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NISTCVSS:3.1/AV:N/AC:L/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-787Out-of-bounds Write
T1499.004Application 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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