Pingvin Share X from 0.19.0 before 1.22.0 contains an improper authentication vulnerability that allows remote unauthenticated attackers to take over accounts by abusing automatic OAuth email linking in OAuthService.signUp(). Attackers can register a victim's unverified email on an enabled OAuth/OIDC provider, exploiting the missing emailverified check in GenericOidcProvider, to sign in as the victim including administrators while bypassing TOTP.

Pingvin Share X before 1.22.0 contains a rate limit bypass vulnerability that allows unauthenticated remote attackers to evade per-IP throttling because backend/src/main.ts unconditionally trusts proxy headers. Attackers can rotate spoofed X-Forwarded-For values against /api/auth/signIn, /api/auth/signIn/totp, and /api/auth/resetPassword to brute-force passwords and TOTP codes and forge logged client IP addresses.

Pingvin Share X before 1.22.0 contains an ineffective rate limiting vulnerability because throttler TTL values specified in seconds are interpreted as milliseconds. Unauthenticated attackers can send effectively unthrottled requests to /api/auth/signIn, /api/auth/signIn/totp and /api/auth/resetPassword to brute-force passwords and TOTP codes.