CVE-2025-13166 WSO2 CVE debrief

Who should care

Defenders responsible for user authentication and account security should be aware of this vulnerability and assess their exposure. They should prioritize verifying the presence of this vulnerability in their systems and take steps to mitigate the risk of enumeration and subsequent attacks.

Why it matters

Defenders should prioritize verifying the presence of this vulnerability in their systems, especially if they use SMS OTP for user authentication. They should assess the potential exposure of their user accounts and take steps to mitigate the risk of enumeration and subsequent attacks. The impact is amplified for accounts that have not configured a mobile number.

• Enumeration of valid usernames can facilitate subsequent brute force attacks.
• Enumeration of valid usernames can facilitate social engineering attempts.
• Discovery of usernames can lead to information leakage.
• Reputational damage and loss of customer trust are potential consequences of a successful attack.

Technical summary

The SMS OTP flow fails to adequately handle error messages, allowing an attacker to infer the existence of registered user accounts based on the responses received during the OTP initiation process. This weakness can be exploited by an attacker to discover valid usernames within the system. The impact is amplified for accounts that have not configured a mobile number, as the enumeration is specifically tied to this condition. Defenders should prioritize verifying the presence of this vulnerability in their systems, especially if they use SMS OTP for user authentication.

Defensive priority

Defenders should prioritize verifying the presence of this vulnerability in their systems, especially if they use SMS OTP for user authentication. They should also assess the potential exposure of their user accounts and take steps to mitigate the risk of enumeration and subsequent attacks.

Recommended defensive actions

• Verify the presence of this vulnerability in your systems, especially if you use SMS OTP for user authentication.
• Assess the potential exposure of your user accounts and take steps to mitigate the risk of enumeration and subsequent attacks.
• Consider implementing additional security measures to prevent brute force attacks and social engineering attempts.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record and NVD entry provide information about the vulnerability, but the details are limited. The vendor and product information is not confirmed, and the CVSS score is 3.7, indicating a low severity.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.