{"id":55255,"date":"2025-06-26T21:05:51","date_gmt":"2025-06-26T21:05:51","guid":{"rendered":""},"modified":"2025-09-02T21:31:44","modified_gmt":"2025-09-03T03:31:44","slug":"cve-2025-35940-hard-coded-jwt-signing-key-vulnerability-in-archiverspaapi-asp-net-application","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-35940-hard-coded-jwt-signing-key-vulnerability-in-archiverspaapi-asp-net-application\/","title":{"rendered":"CVE-2025-35940: Hard-coded JWT Signing Key Vulnerability in ArchiverSpaApi ASP.NET Application<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

The vulnerability designated as CVE-2025-35940 is a critical flaw discovered in the ArchiverSpaApi ASP.NET application. This application’s security vulnerability<\/a> arises from the use of a hard-coded JSON Web Token (JWT) signing key. The flaw potentially affects all entities that utilize the affected application, and could lead to unauthorized<\/a> access, system compromise, or data leakage. The severity of this vulnerability<\/a> highlights the importance of robust cybersecurity practices, especially in the area of access control and authentication management.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-35940
\nSeverity: High (CVSS: 8.1)
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: Unauthorized access to protected API endpoints<\/a>, potential system compromise and data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

ArchiverSpaApi ASP.NET Application | All versions prior<\/a> to the patch<\/p>\n

How the Exploit Works<\/strong><\/p>\n

The CVE-2025-35940 vulnerability stems from the application’s<\/a> use of a hard-coded JWT signing key. This key is used to verify the integrity of JWT tokens, which are often used for user authentication and access control<\/a>. An attacker with knowledge of this key can generate and sign their own JWT<\/a> tokens. These tokens would be accepted as valid by the application, granting the attacker access<\/a> to protected API endpoints.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

An attacker might exploit this vulnerability via<\/a> a HTTP request like the one below. In this example, the attacker crafts a malicious JWT token (“eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9…”) using the hard-coded signing key<\/a> and includes it in the Authorization header:<\/p>\n

POST \/protected\/endpoint HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\nAuthorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...\n{ \"malicious_payload\": \"...\" }<\/code><\/pre>\n
This request would be accepted by the server as if it were from an authenticated user, allowing the attacker to perform actions or access<\/a> data they should not be able to.<\/p>\n
Guidance on Mitigation and Patching<\/strong><\/p>\n
The recommended mitigation for this vulnerability<\/a> is to apply the vendor-supplied patch, which replaces the hard-coded signing key with a secure, randomly generated one. If the patch cannot be applied immediately, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used as a temporary mitigation measure. These systems can be configured to block requests containing<\/a> known malicious JWT tokens. However, this is a stop-gap measure and not a full solution; the vendor’s patch should be applied as soon as possible.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview The vulnerability designated as CVE-2025-35940 is a critical flaw discovered in the ArchiverSpaApi ASP.NET application. This application’s security vulnerability arises from the use of a hard-coded JSON Web Token (JWT) signing key. The flaw potentially affects all entities that utilize the affected application, and could lead to unauthorized access, system compromise, or data leakage. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-55255","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t