#oauth

A recent investigation by cybersecurity researchers at Oasis Security has revealed a data overreach in how Microsoft’s OneDrive…

### Summary [Amazon Redshift Python Connector](https://docs.aws.amazon.com/redshift/latest/mgmt/python-redshift-driver.html) is a pure Python connector to Redshift (i.e., driver) that implements the [Python Database API Specification 2.0](https://www.python.org/dev/peps/pep-0249/). When the Amazon Redshift Python Connector is configured with the BrowserAzureOAuth2CredentialsProvider plugin, the driver skips the SSL certificate validation step for the Identity Provider. ### Impact An insecure connection could allow an actor to intercept the token exchange process and retrieve an access token. **Impacted versions:** >=2.0.872;<=2.1.6 ### Patches Upgrade Amazon Redshift Python Connector to version 2.1.7 and ensure any forked or derivative code is patched to incorporate the new fixes. ### Workarounds None ### References If you have any questions or comments about this advisory we ask that you contact AWS/Amazon Security via our vulnerability reporting page [1] or directly via em...

Cybersecurity researchers have discovered a security flaw in Microsoft's OneDrive File Picker that, if successfully exploited, could allow websites to access a user's entire cloud storage content, as opposed to just the files selected for upload via the tool. "This stems from overly broad OAuth scopes and misleading consent screens that fail to clearly explain the extent of access being granted,

In Jenkins WSO2 Oauth Plugin 1.0 and earlier, authentication claims are accepted without validation by the "WSO2 Oauth" security realm, allowing unauthenticated attackers to log in to controllers using this security realm using any username and any password, including usernames that do not exist.

### Summary PKCE was implemented in the OAuth implementation in workers-oauth-provider that is part of[ MCP framework](https://github.com/cloudflare/workers-mcp). However, it was found that an attacker could cause the check to be skipped. ### Impact PKCE is a defense-in-depth mechanism against certain kinds of attacks and was an optional extension in OAuth 2.0 which became required in the OAuth 2.1 draft. (Note that the MCP specification requires OAuth 2.1.) This bug completely bypasses PKCE protection. ### Patches Fixed in: https://github.com/cloudflare/workers-oauth-provider/pull/27 We patched up the vulnerabilities in the latest version, v 0.0.5 of the Workers OAuth provider (https://www.npmjs.com/package/@cloudflare/workers-oauth-provider). You'll need to update your MCP servers to use that version to resolve the vulnerability. ### Workarounds None

### Summary PKCE was implemented in the OAuth implementation in workers-oauth-provider that is part of[ MCP framework](https://github.com/cloudflare/workers-mcp). However, it was found that an attacker could cause the check to be skipped. ### Impact Under certain circumstances (see below), if a victim had previously authorized with a server built on workers-oath-provider, and an attacker could later trick the victim into visiting a malicious web site, then attacker could potentially steal the victim's credentials to the same OAuth server and subsequently impersonate them. In order for the attack to be possible, the OAuth server's authorized callback must be designed to auto-approve authorizations that appear to come from an OAuth client that the victim has authorized previously. The authorization flow is not implemented by workers-oauth-provider; it is up to the application built on top to decide whether to implement such automatic re-authorization. However, many applications do impl...

# Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-4pc9-x2fx-p7vj. This link is maintained to preserve external references. # Original Description The OAuth implementation in workers-oauth-provider that is part of MCP framework https://github.com/cloudflare/workers-mcp , did not correctly validate that redirect_uri was on the allowed list of redirect URIs for the given client registration. Fixed in:  https://github.com/cloudflare/workers-oauth-provider/pull/26 https://github.com/cloudflare/workers-oauth-provider/pull/26 Impact: Under certain circumstances (see below), if a victim had previously authorized with a server built on workers-oath-provider, and an attacker could later trick the victim into visiting a malicious web site, then attacker could potentially steal the victim's credentials to the same OAuth server and subsequently impersonate them. In order for the attack to be possible, the OAuth server's authorized callback must be des...

# Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-qgp8-v765-qxx9. This link is maintained to preserve external references. # Original Description PKCE was implemented in the OAuth implementation in workers-oauth-provider that is part of MCP framework https://github.com/cloudflare/workers-mcp . However, it was found that an attacker could cause the check to be skipped. Fixed in: https://github.com/cloudflare/workers-oauth-provider/pull/27 https://github.com/cloudflare/workers-oauth-provider/pull/27 Impact: PKCE is a defense-in-depth mechanism against certain kinds of attacks and was an optional extension in OAuth 2.0 which became required in the OAuth 2.1 draft. (Note that the MCP specification requires OAuth 2.1.). This bug completely bypasses PKCE protection.

Multiple suspected Russia-linked threat actors are "aggressively" targeting individuals and organizations with ties to Ukraine and human rights with an aim to gain unauthorized access to Microsoft 365 accounts since early March 2025. The highly targeted social engineering operations, per Volexity, are a shift from previously documented attacks that leveraged a technique known as device code

All Google accounts could end up compromised by a clever replay attack on Gmail users that abuses Google infrastructure.