Cyber Resilience

CVE-2023-31475

Memory Safety in Gl-Inet Gl-S20 Firmware ≤ 3.216

Public PoCMemory Safety
Published
11 May 2023
Modified
27 January 2025
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.14 96th percentile
Risk Priority 85 floored blend · peak EPSS

Summary

CVE-2023-31475 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Gl-Inet Gl-S20 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-31475 is a buffer overflow vulnerability in the guci2_get() function within libglutil.so on GL.iNet devices running firmware versions prior to 3.216. The flaw occurs when an item is retrieved from a UCI context and its value is copied into a fixed-size character buffer without performing a bounds check.

The vulnerability can be exploited remotely by unauthenticated attackers over the network. Successful exploitation grants full control over confidentiality, integrity, and availability, enabling outcomes such as arbitrary code execution or device takeover, consistent with the CVSS 9.8 rating.

Vendor references direct users to firmware 3.216 and later releases that address the issue. The associated EPSS score rose from lower values to a peak of 0.2581 before receding to the current 0.2211, indicating measurable post-disclosure exploitation interest.

EU & UK References

Vulnerability Data

An issue was discovered on GL.iNet devices before 3.216. The function guci2_get() found in libglutil.so has a buffer overflow when an item is requested from a UCI context, and the value is pasted into a char pointer to a buffer…

more

without checking the size of the buffer.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-31473Same product: Gl-Inet Gl-A1300
CVE-2023-31477Same product: Gl-Inet Gl-A1300
CVE-2023-31474Same product: Gl-Inet Gl-A1300
CVE-2023-31478Same product: Gl-Inet Gl-A1300
CVE-2023-31471Same product: Gl-Inet Gl-A1300
CVE-2023-31472Same product: Gl-Inet Gl-A1300
CVE-2023-50445Same product: Gl-Inet Gl-A1300
CVE-2023-50922Same product: Gl-Inet Gl-A1300
CVE-2023-50921Same product: Gl-Inet Gl-A1300
CVE-2023-50919Same product: Gl-Inet Gl-A1300

Affected Assets

gl-inet
gl-s20 firmware
≤ 3.216
gl-inet
gl-x3000 firmware
≤ 3.216
gl-inet
gl-mt3000 firmware
≤ 3.216
gl-inet
gl-mt2500 firmware
≤ 3.216
gl-inet
gl-mt2500a firmware
≤ 3.216
gl-inet
gl-axt1800 firmware
≤ 3.216
gl-inet
gl-a1300 firmware
≤ 3.216
gl-inet
gl-ax1800 firmware
≤ 3.216
gl-inet
gl-sft1200 firmware
≤ 3.216
gl-inet
gl-mt1300 firmware
≤ 3.216
+22 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.2.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-120

Platform-independent managed code eliminates the need for unchecked native buffer copies that are the root cause of classic buffer overflows.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.

ID.RA-01 partial match
prevents

Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.

finds

Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.

prevents

Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.

prevents

Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.

prevents

Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.

References