Tag: microsoft

  • Critical Elevation of Privilege via NTLMv1 in Windows (CVE-2025-21311)

    Overview

    CVE-2025-21311 is a critical vulnerability in Microsoft’s implementation of the NTLM version 1 (NTLMv1) authentication protocol. This flaw permits an attacker to gain elevated privileges through network-based exploitation, impacting various supported versions of Windows, including Windows Server 2025 and Windows 11 24H2.

    Technical Details

    The vulnerability stems from an incorrect implementation of authentication algorithms, categorized under CWE-303: Incorrect Implementation of Authentication Algorithm. Specifically, the use of the outdated and insecure NTLMv1 allows attackers to craft or intercept authentication messages, potentially leading to privilege escalation.

    Unlike its successor NTLMv2, NTLMv1 lacks modern cryptographic protections and is more susceptible to relay attacks and credential manipulation. This vulnerability is especially dangerous in domain environments where NTLM is still supported for backward compatibility.

    CVSS Score and Severity

    This vulnerability has been assessed with a CVSS v3.1 base score of 9.8 (Critical), with the following vector:

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

    • Attack Vector: Network
    • Attack Complexity: Low
    • Privileges Required: None
    • User Interaction: None
    • Impact: High on confidentiality, integrity, and availability

    This combination indicates that the flaw is easily exploitable and can cause significant harm if leveraged by a malicious actor.

    Affected Systems

    • Windows Server 2025 (x64, Server Core) – Versions before 10.0.26100.2894
    • Windows Server 2022, 23H2 Edition – Versions before 10.0.25398.1369
    • Windows 11 24H2 (ARM64 & x64) – Versions before 10.0.26100.2894

    Mitigation and Recommendations

    Microsoft has addressed this vulnerability in cumulative updates released after January 2025. Organizations should:

    • Ensure systems are updated to the latest security patches.
    • Disable NTLMv1 wherever possible and enforce the use of NTLMv2 or Kerberos for authentication.
    • Audit authentication logs for anomalous NTLM traffic.

    Conclusion

    CVE-2025-21311 highlights the critical risks of legacy protocol support in modern systems. NTLMv1 has long been deprecated, and its continued use poses serious security threats. Organizations must act quickly to update systems and eliminate NTLMv1 reliance to prevent exploitation.

    For more details, refer to the official Microsoft advisory: MSRC: CVE-2025-21311

  • CVE-2025-29814: Critical Privilege Escalation in Microsoft Partner Center

    Overview

    On March 21, 2025, Microsoft disclosed a critical security vulnerability identified as CVE-2025-29814 in the Microsoft Partner Center. This flaw allows an authorized attacker to escalate privileges across a network due to improper authorization mechanisms.

    The issue has been categorized under CWE-20: Improper Input Validation. It carries a CVSS 3.1 base score of 9.3, classifying it as a critical vulnerability.

    What is Microsoft Partner Center?

    The Microsoft Partner Center is an administrative platform for managing partner relationships, customer subscriptions, and billing across Microsoft services. It serves as a central hub for service provisioning, making it a high-value target for attackers seeking to exploit privilege escalation weaknesses.

    Technical Details

    The vulnerability stems from improper authorization validation in the Microsoft Partner Center API. While exact implementation details are not public, Microsoft has confirmed that an attacker with basic access rights can exploit the flaw to gain elevated privileges on the system. This allows for actions typically reserved for higher-privilege accounts, such as administrative functions.

    • CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:H
    • Severity: Critical (9.3)
    • Attack Vector: Network
    • Privileges Required: None
    • User Interaction: Required
    • Scope: Changed
    • Impact: High on integrity and availability

    Understanding CVSS 3.1 Metrics

    The CVSS (Common Vulnerability Scoring System) is a framework used to assess the severity of software vulnerabilities. This CVE’s high score of 9.3 indicates significant potential for damage if exploited, especially considering the ease of exploitation (low complexity) and the absence of required privileges.

    Security Classification: CWE-20

    CWE-20 refers to Improper Input Validation, where an application does not properly check the inputs it receives. In this case, failure to validate authorization credentials allows privilege escalation. This is a common and dangerous class of vulnerability due to its potential to affect system-wide security.

    Exploitation Status and Impact

    According to CISA’s SSVC (Stakeholder-Specific Vulnerability Categorization), exploitation of this vulnerability had not been observed at the time of disclosure. However, the technical impact is rated as total, emphasizing the urgency for mitigation.

    While the flaw is in a cloud-hosted platform, system administrators and partners relying on Microsoft Partner Center should apply any available patches or mitigations immediately and audit account activity for suspicious behavior.

    Mitigation and Recommendations

    • Follow Microsoft’s official advisory for updates: CVE-2025-29814 Advisory
    • Enable monitoring and alerting on all administrative activity
    • Review user access privileges and implement the principle of least privilege
    • Apply available patches or updates provided by Microsoft

    Conclusion

    CVE-2025-29814 highlights the critical importance of proper authorization in cloud service platforms. The potential for widespread privilege escalation demands immediate attention from affected organizations. Stay vigilant and prioritize timely updates and access control reviews.

  • CVE-2025-47733: Critical SSRF Vulnerability in Microsoft Power Apps

    Overview

    CVE-2025-47733 is a critical Server-Side Request Forgery (SSRF) vulnerability identified in Microsoft Power Apps. This flaw allows unauthorized remote attackers to exploit improperly handled server-side requests, potentially disclosing sensitive internal information across the network.

    What is SSRF?

    Server-Side Request Forgery (SSRF) vulnerabilities occur when an attacker can manipulate a server to make unauthorized requests to internal or external services on their behalf. This is especially dangerous in cloud-based and internal environments where attackers can access resources that are not exposed to the public internet.

    In this case, Microsoft Power Apps is vulnerable to SSRF due to insufficient input validation, allowing attackers to craft URLs that the server processes, potentially leaking internal data.

    Technical Details

    This vulnerability is categorized as CWE-918: Server-Side Request Forgery (SSRF). The flaw allows:

    • Remote attackers with no prior access to craft requests that the server will forward to internal services
    • Unauthorized disclosure of sensitive information
    • No user interaction or credentials required

    CVSS Severity

    According to the Common Vulnerability Scoring System (CVSS) v3.1, the vulnerability has a base score of 9.1 (Critical):

    • Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
    • Confidentiality Impact: High
    • Integrity Impact: High

    This score reflects the ease of exploitation and the potential severity of unauthorized data access and manipulation.

    SSVC Assessment

    The CISA Stakeholder-Specific Vulnerability Categorization (SSVC) analysis outlines:

    • No known exploitation as of publication
    • Vulnerability is automatable
    • Technical impact is considered total

    These factors highlight the urgency of addressing the issue before exploitation tools emerge.

    Mitigation Guidance

    Microsoft has released guidance and updates for mitigating this vulnerability. Recommended steps include:

    • Apply patches or updates provided by Microsoft through the MSRC advisory
    • Review and harden any inputs that lead to server-side network calls
    • Monitor internal service access for anomalies

    References

    Organizations using Microsoft Power Apps should prioritize patching and review network configurations to prevent unauthorized internal access. SSRF vulnerabilities are particularly dangerous in cloud and microservice environments where internal trust boundaries are critical.