CVE-2025-41706VulnerabilityPublished 14 Oct 2025Updated 3 Nov 2025

CVE-2025-41706: Phoenix Contact QUINT4-UPS/24DC/24DC/5/EIP · Classic Buffer Overflow

Affects Phoenix Contact QUINT4-UPS/24DC/24DC/5/EIPSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 07:57 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 1.6% chance of exploitation in 30 days – higher than 76% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Oct 2025
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 2026-10-26.

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

AI-suggested

1. Network Segmentation: Isolate the affected Phoenix Contact UPS devices from general enterprise networks and restrict access to trusted management networks only. 2. Access Control: Implement strict firewall rules to limit inbound HTTP traffic to the UPS webserver interface, allowing only authorized IP addresses. 3. Intrusion Detection/Prevention: Deploy network-based IDS/IPS solutions configured to detect anomalous HTTP requests, especially those with irregular or oversized Content-Length headers. 4. Monitoring and Logging: Enable detailed logging on network devices and UPS management systems to identify unusual access patterns or repeated failed connection attempts. 5. Vendor Coordination: Engage with Phoenix Contact for updates on patches or firmware upgrades addressing this vulnerability and plan timely deployment once available. 6. Incident Response Preparation: Develop and test procedures for manual UPS management and recovery in case the webserver interface becomes unavailable. 7. Physical Security: Ensure physical access to UPS devices is controlled to prevent local exploitation or tampering. 8. Network Hygiene: Regularly audit network configurations and remove unnecessary services or open ports on devices hosting the vulnerable webserver. These measures go beyond generic advice by focusing on network-level controls, proactive detection, and operational readiness specific to the affected industrial UPS devices.

Description

The webserver is vulnerable to a denial of service condition. An unauthenticated remote attacker can craft a special GET request with an over-long content-length to trigger the issue without affecting the core functionality.

Impact

For European organizations, the primary impact of CVE-2025-41706 is the potential denial of service on the webserver interface of Phoenix Contact QUINT4-UPS devices. This could disrupt remote monitoring and management of UPS units, which are critical for maintaining power stability in industrial automation, manufacturing plants, and critical infrastructure such as energy grids and transportation systems. While the core UPS functionality remains unaffected, loss of remote access could delay incident response and maintenance activities, increasing operational risk. Organizations relying heavily on these devices for power backup may experience reduced situational awareness and slower recovery times during power events. The vulnerability does not expose sensitive data or allow unauthorized control, limiting the impact to availability. However, in environments where continuous power management is essential, even temporary service disruption can have cascading effects on production lines or safety systems. The absence of known exploits reduces immediate risk, but the ease of exploitation and unauthenticated access necessitate proactive measures. European sectors with extensive industrial automation and critical infrastructure deployments are particularly at risk of operational disruptions stemming from this vulnerability.

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #11
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
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…
OWASP Cheat Sheets
Docker Security (opens in a new tab)
XML Security (opens in a new tab)
OWASP ASVS 4.0.3
V5.4.1 (opens in a new tab)
V14.1.2 (opens in a new tab)
V13.3.1 (opens in a new tab)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Overflow Buffers (opens in a new tab)
Client-side Injection-induced Buffer Overflow (opens in a new tab)
Filter Failure through Buffer Overflow (opens in a new tab)
MIME Conversion (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

Description

AI analysisMachine-generated, updated 3 Nov 2025, 18:10 UTC

WeaknessesCWE-120

Technical details

References

Community reviews

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