CVE-2025-0696Network attack vector

Component crash via unchecked JSON key pointer

Published Jan 27, 2025 · Updated Feb 12, 2025

NULL pointer dereference in Cesanta Frozen before 1.7 allows remote attackers to crash an embedding component via crafted JSON input. The json_next_elem path passes a null or negative-length key name to next_set_key, whose array branch calls atoi on the unchecked pointer. Exploitation requires an embedding application to pass attacker-controlled JSON to the affected API; the documented consequence is a process crash only.

CVSS severity5.3
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Cesanta Frozen before 1.7 allows remote attackers to crash an embedding component via crafted JSON input. The json_next_elem path passes a null or negative-length key name to next_set_key, whose array branch calls atoi on the unchecked pointer. Exploitation requires an embedding application to pass attacker-controlled JSON to the affected API; the documented consequence is a process crash only.

The record

CVE
CVE-2025-0696
Published
Jan 27, 2025
Updated
Feb 12, 2025
Vendor
Cesanta
Product
Frozen
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 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?

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

  1. Affected versionversion=0 <1.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Cesanta · Frozenversion=0 <1.7

Published CVSS scores

5.3Nozomi NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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