VulnerabilityPublished 21 Jun 2025Updated 28 Jul 2025

CVE-2025-52916: Yealink RPS · Improper Restriction of Excessive Authentication Attempts

Affects Yealink RPSSource CVE Database V5

Not known to be exploited · CVSS 2.2 Low.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score

2.2Low

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Jun 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 26 Oct 2026.

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 or the CVSS exploit maturity 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
Yealink RPS	Affected =0	Fixed in–

AI-suggested

To mitigate this vulnerability, European organizations should implement the following specific measures: 1) Monitor and restrict access to the Yealink RPS interface, ensuring that only authorized personnel with necessary privileges can perform SN verification. 2) Employ network segmentation and firewall rules to limit exposure of the RPS service to trusted internal networks or VPNs. 3) Implement custom rate limiting or anomaly detection on SN verification requests to detect and block brute-force attempts, even if the vendor patch is not yet available. 4) Maintain strict access control policies and audit logs to detect suspicious activities related to serial number enumeration. 5) Stay updated with Yealink security advisories and apply patches promptly once released. 6) Consider additional authentication mechanisms or multi-factor authentication for accessing provisioning services to increase the difficulty of unauthorized access. 7) Educate IT staff about this vulnerability and encourage vigilance against potential follow-on attacks that could leverage enumerated serial numbers.

Description

Yealink RPS before 2025-06-04 lacks SN verification attempt limits, enabling brute-force enumeration (last five digits).

Impact

For European organizations using Yealink RPS for device provisioning and management, this vulnerability could lead to unauthorized disclosure of device serial numbers. While the direct impact on system integrity and availability is negligible, the exposure of serial numbers may facilitate further reconnaissance and targeted attacks, such as unauthorized device registration, spoofing, or social engineering campaigns. Given that Yealink devices are widely used in enterprise telephony and unified communications across Europe, attackers could leverage this information to undermine trust in communication infrastructure or gain footholds for more sophisticated attacks. However, the requirement for high privileges and network access limits the ease of exploitation, reducing immediate risk. Nonetheless, organizations with large deployments of Yealink devices should consider this vulnerability as part of their risk management, especially in sectors where secure communications are critical, such as government, finance, and healthcare.

CWE-307Improper Restriction of Excessive Authentication Attempts (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
Architecture and Design
Common protection mechanisms include: Disconnecting the user after a small number of failed attempts; Implementing a timeout; Locking out a targeted account; Requiring a computational task on the user's part.
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.
OWASP Cheat Sheets
Authentication (opens in a new tab)
Transport Layer Protection (opens in a new tab)
TLS Cipher String (opens in a new tab)
OWASP ASVS 4.0.3
V2.2.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
Attack patterns
Dictionary-based Password Attack (opens in a new tab)
Password Brute Forcing (opens in a new tab)
Password Spraying (opens in a new tab)
Credential Stuffing (opens in a new tab)
Use of Known Kerberos Credentials (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 29 Jul 2025, 01:00 UTC

WeaknessesCWE-307

Technical details

References

Community reviews

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