Sławomir Rozbicki

**Name of the Vulnerable Software and Affected Versions** MikroTik RouterOS versions prior to 6.49.21 MikroTik RouterOS versions prior to 7.23.4 MikroTik RouterOS versions prior to 7.24.2 **Description** RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures during X.509 validation. Due to the inclusion of an e=3 root CA in its trust store, an attacker who controls or redirects an outbound TLS connection can utilize the root public certificate to forge a trusted intermediate certificate and issue certificates for arbitrary hostnames, allowing for TLS server impersonation. **Recommendations** Update to version 6.49.21 (Long-term). Update to version 7.23.4 (Long-term). Update to version 7.24.2 (Stable).

**Name of the Vulnerable Software and Affected Versions** RouterOS versions prior to 6.49.21 RouterOS versions prior to 7.23.4 RouterOS versions prior to 7.24.2 **Description** An issue exists where the SSH server enters the connection protocol following a client-requested rekey without requiring user authentication. This allows an unauthenticated client to open a session channel and send an exec request. The server then dispatches the command, which enables the unauthenticated creation, overwrite, and reconstruction of files within the managed file namespace, including support files that contain diagnostic data and configuration. **Recommendations** Update to version 6.49.21 or later for the Long-term branch. Update to version 7.23.4 or later for the Long-term branch. Update to version 7.24.2 or later for the Stable branch.

**Name of the Vulnerable Software and Affected Versions** RouterOS versions prior to 6.49.21 RouterOS versions prior to 7.23.4 RouterOS versions prior to 7.24.2 **Description** WebFig contains an unauthenticated file-read issue in the '/jsproxy' endpoint. A newly allocated session retains a stale uninitialized principal pointer used for file authorization. An unauthenticated attacker can manipulate the allocator to cause the file-serving path to dereference this pointer with elevated rights. By supplying parent-directory components in an encrypted URI, the attacker can escape the WebFig file namespace and disclose root-owned files, such as configuration stores containing credentials. **Recommendations** Update to version 6.49.21 (Long-term). Update to version 7.23.4 (Long-term). Update to version 7.24.2 (Stable).

**Name of the Vulnerable Software and Affected Versions** RouterOS versions prior to 6.49.21 RouterOS versions prior to 7.23.4 RouterOS versions prior to 7.24.2 **Description** An authentication bypass exists in the SSH public key verification process. The system fails to compare the complete RSA public key when matching an authentication request to an authorized user key, verifying only the key type and modulus while omitting the exponent. An attacker who knows an authorized RSA modulus can provide a key with an exponent of one to forge a valid signature and open an SSH command channel as the target user without possessing the private key. This issue has been exploited in the wild. **Recommendations** Update to version 6.49.21 (Long-term). Update to version 7.23.4 (Long-term). Update to version 7.24.2 (Stable).

**Name of the Vulnerable Software and Affected Versions** RouterOS versions prior to 6.49.21 RouterOS versions prior to 7.23.4 RouterOS versions prior to 7.24.2 **Description** An unauthenticated client can initiate an IPv4 UDP test by exploiting a state where the system accepts a related btest connection before the primary session authentication is complete. When the `random-data` variable is set to `false`, the sender transmits an uninitialized tail from a kernel packet buffer. Additionally, an unchecked, inverted packet-size interval leads to an unsigned integer underflow, resulting in anomalously large fragmented output and a potential restart of the RouterOS kernel. **Recommendations** Update to version 6.49.21 (Long-term). Update to version 7.23.4 (Long-term). Update to version 7.24.2 (Stable).

**Name of the Vulnerable Software and Affected Versions** RouterOS versions prior to 6.49.21 RouterOS versions prior to 7.23.4 RouterOS versions prior to 7.24.2 **Description** An argument-handling flaw exists in the SSH login path when usernames begin with a prohibited character. This allows an unauthenticated user to reach the RouterOS login helper and change the trusted RouterOS policy mask, resulting in privilege escalation. **Recommendations** Update to version 6.49.21 or later for the Long-term release. Update to version 7.23.4 or later for the Long-term release. Update to version 7.24.2 or later for the Stable release.