CVE-2023-25124VulnerabilityPublished 6 Jul 2023Updated 4 Nov 2025

CVE-2023-25124: Milesight UR32L · Stack-based Buffer Overflow

Affects Milesight UR32LSource CVE Database V5

Not known to be exploited · CVSS 7.2 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.2High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.5% chance of exploitation in 30 days – higher than 74% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Jul 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Milesight UR32L	Affected =32.3.0.5	Fixed in–

AI-suggested

1. Immediately restrict HTTP access to the vtysh_ubus interface to trusted administrators only, ideally via network segmentation and firewall rules. 2. Implement strict access controls and multi-factor authentication for administrative interfaces to reduce the risk of privilege escalation. 3. Monitor network traffic for unusual or malformed HTTP requests targeting the OpenVPN client configuration endpoints. 4. Regularly audit device configurations and logs for signs of exploitation attempts or anomalous behavior. 5. Engage with the vendor, Milesight, to obtain patches or firmware updates addressing this vulnerability as soon as they become available. 6. If patching is not immediately possible, consider disabling or restricting the vulnerable OpenVPN client configuration functionality temporarily. 7. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting exploitation attempts targeting this vulnerability. 8. Educate network administrators about the risks and signs of exploitation related to this vulnerability to improve incident response readiness.

Description

Multiple buffer overflow vulnerabilities exist in the vtysh_ubus binary of Milesight UR32L v32.3.0.5 due to the use of an unsafe sprintf pattern. A specially crafted HTTP request can lead to arbitrary code execution. An attacker with high privileges can send HTTP requests to trigger these vulnerabilities.This buffer overflow occurs in the set_openvpn_client function with the remote_subnet and the remote_mask variables.

Impact

For European organizations, the impact of this vulnerability is significant. The Milesight UR32L is commonly deployed in industrial control systems, enterprise branch offices, and critical infrastructure sectors that rely on secure VPN connections for remote access. Exploitation could allow attackers to execute arbitrary code on these devices, leading to full compromise of the router. This could result in interception or manipulation of VPN traffic, unauthorized network access, disruption of business operations, and potential lateral movement within the network. Confidentiality of sensitive data transmitted over VPNs could be breached, integrity of network configurations compromised, and availability of network services disrupted. Given the high privileges required, exploitation is more likely in environments where administrative access is not tightly controlled. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially from targeted attackers. European organizations in sectors such as manufacturing, energy, transportation, and government are particularly at risk due to their reliance on secure network infrastructure and VPN technologies.

CWE-121Stack-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #14
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Implementation
Implement and perform bounds checking on input.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2025, 20:48 UTC

WeaknessesCWE-121

Technical details

References

Community reviews

Related threats