Threat database

Memos before 0.27.0 contains a missing authorization vulnerability in the ActivityService ListActivities and GetActivity API methods that allows authenticated users to view all users' activity records. Low-privileged attackers can enumerate sequential activity IDs to obtain creator IDs, timestamps, and memo-comment references, including activity on other users' private memos.

Memos versions 0.26.0 through 0.30.0 fail to revoke refresh tokens when a user changes their password, allowing attackers to maintain account access. An attacker with a stolen refresh token can call the RefreshToken RPC to obtain new access tokens and rotate the refresh token indefinitely, bypassing the password change security measure.

Memos versions up to 0.30.0 have a Server-Side Request Forgery (SSRF) vulnerability due to omission of the 100.64.0.0/10 carrier-grade NAT address range from SSRF protections in the link-metadata fetcher. This allows unauthenticated attackers to bypass IP validation and make the server request internal hosts in that range, including cloud metadata services, potentially reading page titles and descriptions.

Memos' webhook dispatch function safeDialContext (internal/webhook/webhook.go) resolves the target hostname via net.DefaultResolver.LookupHost and validates the resulting IPs against reserved ranges, but then dials net.JoinHostPort(host, port) using the original hostname rather than the already-validated IP address.

Memos' webhook URL validation, isReservedIP (internal/webhook/validate.go), checks a candidate IP against a reservedCIDRs list that omits 0.0.0.0/8 and never calls ip.IsUnspecified — unlike the correctly implemented sibling function isInternalIP in internal/httpgetter/html_meta.go, which does.

A weakness has been identified in usememos memos up to 0.22.1. This affects the function memos_access_token of the file src/App.tsx of the component UpdateInstanceSetting. This manipulation of the argument additionalStyle/additionalScript causes improper authorization. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Memos is a privacy-first, lightweight note-taking service that uses Access Tokens to authenticate application access. When a user changes their password, the existing list of Access Tokens stay valid instead of expiring. If a user finds that their account has been compromised, they can update their password. In versions up to and including 0.18.1, though, the bad actor will still have access to their account because the bad actor's Access Token stays on the list as a valid token. The user will have to manually delete the bad actor's Access Token to secure their account. The list of Access Tokens has a generic Description which makes it hard to pinpoint a bad actor in a list of Access Tokens. A known patched version of Memos isn't available. To improve Memos security, all Access Tokens will need to be revoked when a user changes their password. This removes the session for all the user's devices and prompts the user to log in again. One can treat the old Access Tokens as "invalid" because those Access Tokens were created with the older password.