CVE-2023-31475Public exploitNetwork attack vector

API service crash via unchecked UCI value copy

Published May 11, 2023 · Updated Jan 27, 2025

Stack-based buffer overflow in GL.iNet router firmware 3.215 and earlier allows remote authenticated users to crash the API service. The guci2_get function passes an unbounded UCI value to sprintf, which copies it into a caller-supplied fixed-size buffer without receiving or checking that buffer's length. The demonstrated timezone path requires an API authorization token; an oversized valid zone name overwrites the stack canary and terminates API request processing.

CVSS severity9.0
Critical
EPSS probability13.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in GL.iNet router firmware 3.215 and earlier allows remote authenticated users to crash the API service. The guci2_get function passes an unbounded UCI value to sprintf, which copies it into a caller-supplied fixed-size buffer without receiving or checking that buffer's length. The demonstrated timezone path requires an API authorization token; an oversized valid zone name overwrites the stack canary and terminates API request processing.

The record

CVE
CVE-2023-31475
Published
May 11, 2023
Updated
Jan 27, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 27, 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.0CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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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