CVE-2021-39157Public exploitNetwork attack vector

Process crash via unchecked null charset result

Published Aug 24, 2021 · Updated Aug 4, 2024

Improper exception handling in Sonicdoe detect-character-encoding 0.6.0 and earlier allows attackers to crash a Node.js process via unmatched input. The DetectCharacterEncoding native wrapper passes a null result from ICU's ucsdet_detect function to ucsdet_getName without checking it, causing a segmentation fault. Exploitation requires a consuming application to pass attacker-controlled bytes to the library; the resulting crash interrupts that Node.js service.

CVSS severity7.5
High
EPSS probability2.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper exception handling in Sonicdoe detect-character-encoding 0.6.0 and earlier allows attackers to crash a Node.js process via unmatched input. The DetectCharacterEncoding native wrapper passes a null result from ICU's ucsdet_detect function to ucsdet_getName without checking it, causing a segmentation fault. Exploitation requires a consuming application to pass attacker-controlled bytes to the library; the resulting crash interrupts that Node.js service.

The record

CVE
CVE-2021-39157
Published
Aug 24, 2021
Updated
Aug 4, 2024
Vendor
Sonicdoe
Product
detect-character-encoding
Classifications
CWE-755, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=< 0.7.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Sonicdoe · detect-character-encodingversion=< 0.7.0

Published CVSS scores

7.2GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/RL:O/RC:C
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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-755Improper Handling of Exceptional Conditions
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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