RouterOS
RouterOS 5.21
RouterOS 5.21
Third-party support for the RouterOS 5.21: 24/7 engineers manage issues, remediate vulnerabilities, and help you maintain compliance — independent of the vendor contract.
Issue Management
24/7 engineers own your RouterOS 5.21 incidents end to end.
Vulnerability Remediation
Mitigation and patch-around guidance when the vendor no longer ships fixes.
Compliance Maintenance
Controls evidence and documentation that keep auditors satisfied.
Specifications
- product
- routeros
- release
- 5.21
- product Label
- RouterOS
- release Label
- RouterOS 5.21
- codename
- lts
- latest Version
- 5.21
- release Date
- 2012-10-12
- maintained
- source Url
- https://endoflife.date/routeros
OEM vs. 3rd Party Support
See how third-party support compares to the vendor contract for RouterOS 5.21 — monitoring, break/fix, vulnerability work, operations and compliance, before and after EOSL.
| Feature | OEM Support | 3rd Party Support |
|---|---|---|
| Post-EOSL Support | ||
| Break/Fix Support | Until EOSL | |
| 24/7 Monitoring | ||
| Vulnerability Scanning & Remediation | ||
| Managed Operations | ||
| Procedure & Configuration Review | ||
| Compliance & Audit Documentation | Limited | |
| Discounted Migration to Other Platforms |
Why Choose 3rd Party Support for RouterOS 5.21?
Vulnerability Remediation
Scanning, mitigation and patch-around guidance for RouterOS 5.21 when the vendor no longer ships fixes.
Compliance Maintenance
Procedure review, controls evidence and the documentation auditors ask for — maintained continuously, not scrambled at audit time.
24/7 Expert Support
Engineers who know this release monitor, manage and fix issues around the clock — break/fix to managed operations.
RouterOS 5.21 Support: Frequently Asked Questions
Is the RouterOS 5.21 still supported?
Yes. The RouterOS 5.21 is currently supported by RouterOS, and third-party support is available as an alternative — issue management, vulnerability remediation, and compliance help independent of the vendor contract.
How much does third-party support for the RouterOS 5.21 cost?
Typically 40-70% below the OEM maintenance renewal price. Exact pricing depends on quantity, service level and location — request a quote and we respond within 24 hours.
Known Vulnerabilities Affecting RouterOS 5.21
47 published CVEs affect the RouterOS 5.21, including 19 rated critical or high severity. Our 24/7 engineers help you assess exposure, prioritize fixes and apply available patches.
| CVE | Severity | CVSS | Published | Summary |
|---|---|---|---|---|
| CVE-2017-20149 | CRITICAL | 9.8 | Oct 15, 2022 | The Mikrotik RouterOS web server allows memory corruption in releases before Stable 6.38.5 and Long-term 6.37.5, aka Chimay-Red. A remote and unauthenticated user can trigger the vulnerability by sending a crafted HTTP request. An attacker can use this vulnerability to execute arbitrary code on the affected system, as exploited in the wild in mid-2017 and later. |
| CVE-2018-7445 | CRITICAL | 9.8 | Mar 19, 2018 | A buffer overflow was found in the MikroTik RouterOS SMB service when processing NetBIOS session request messages. Remote attackers with access to the service can exploit this vulnerability and gain code execution on the system. The overflow occurs before authentication takes place, so it is possible for an unauthenticated remote attacker to exploit it. All architectures and all devices running RouterOS before versions 6.41.3/6.42rc27 are vulnerable. |
| CVE-2023-30799 | CRITICAL | 9.1 | Jul 19, 2023 | MikroTik RouterOS stable before 6.49.7 and long-term through 6.48.6 are vulnerable to a privilege escalation issue. A remote and authenticated attacker can escalate privileges from admin to super-admin on the Winbox or HTTP interface. The attacker can abuse this vulnerability to execute arbitrary code on the system. |
| CVE-2018-14847 | CRITICAL | 9.1 | Aug 2, 2018 | MikroTik RouterOS through 6.42 allows unauthenticated remote attackers to read arbitrary files and remote authenticated attackers to write arbitrary files due to a directory traversal vulnerability in the WinBox interface. |
| CVE-2022-45313 | HIGH | 8.8 | Dec 5, 2022 | Mikrotik RouterOs before stable v7.5 was discovered to contain an out-of-bounds read in the hotspot process. This vulnerability allows attackers to execute arbitrary code via a crafted nova message. |
| CVE-2019-3976 | HIGH | 8.8 | Oct 29, 2019 | RouterOS 6.45.6 Stable, RouterOS 6.44.5 Long-term, and below are vulnerable to an arbitrary directory creation vulnerability via the upgrade package's name field. If an authenticated user installs a malicious package then a directory could be created and the developer shell could be enabled. |
| CVE-2018-1156 | HIGH | 8.8 | Aug 23, 2018 | Mikrotik RouterOS before 6.42.7 and 6.40.9 is vulnerable to stack buffer overflow through the license upgrade interface. This vulnerability could theoretically allow a remote authenticated attacker execute arbitrary code on the system. |
| CVE-2019-3943 | HIGH | 8.1 | Apr 10, 2019 | MikroTik RouterOS versions Stable 6.43.12 and below, Long-term 6.42.12 and below, and Testing 6.44beta75 and below are vulnerable to an authenticated, remote directory traversal via the HTTP or Winbox interfaces. An authenticated, remote attack can use this vulnerability to read and write files outside of the sandbox directory (/rw/disk). |
| CVE-2023-32154 | HIGH | 7.5 | May 3, 2024 | Mikrotik RouterOS RADVD Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Mikrotik RouterOS. Authentication is not required to exploit this vulnerability. The specific flaw exists within the Router Advertisement Daemon. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverag |
| CVE-2020-20021 | HIGH | 7.5 | Jul 12, 2023 | An issue discovered in MikroTik Router v6.46.3 and earlier allows attacker to cause denial of service via misconfiguration in the SSH daemon. |
| CVE-2019-16160 | HIGH | 7.5 | Oct 7, 2020 | An integer underflow in the SMB server of MikroTik RouterOS before 6.45.5 allows remote unauthenticated attackers to crash the service. |
| CVE-2020-10364 | HIGH | 7.5 | Mar 23, 2020 | The SSH daemon on MikroTik routers through v6.44.3 could allow remote attackers to generate CPU activity, trigger refusal of new authorized connections, and cause a reboot via connect and write system calls, because of uncontrolled resource management. |
| CVE-2018-5951 | HIGH | 7.5 | Mar 2, 2020 | An issue was discovered in Mikrotik RouterOS. Crafting a packet that has a size of 1 byte and sending it to an IPv6 address of a RouterOS box with IP Protocol 97 will cause RouterOS to reboot imminently. All versions of RouterOS that supports EoIPv6 are vulnerable to this attack. |
| CVE-2019-3979 | HIGH | 7.5 | Oct 29, 2019 | RouterOS versions 6.45.6 Stable, 6.44.5 Long-term, and below are vulnerable to a DNS unrelated data attack. The router adds all A records to its DNS cache even when the records are unrelated to the domain that was queried. Therefore, a remote attacker controlled DNS server can poison the router's DNS cache via malicious responses with additional and untrue records. |
| CVE-2019-3978 | HIGH | 7.5 | Oct 29, 2019 | RouterOS versions 6.45.6 Stable, 6.44.5 Long-term, and below allow remote unauthenticated attackers to trigger DNS queries via port 8291. The queries are sent from the router to a server of the attacker's choice. The DNS responses are cached by the router, potentially resulting in cache poisoning |
| CVE-2019-3977 | HIGH | 7.5 | Oct 29, 2019 | RouterOS 6.45.6 Stable, RouterOS 6.44.5 Long-term, and below insufficiently validate where upgrade packages are download from when using the autoupgrade feature. Therefore, a remote attacker can trick the router into "upgrading" to an older version of RouterOS and possibly reseting all the system's usernames and passwords. |
| CVE-2019-13074 | HIGH | 7.5 | Jul 3, 2019 | A vulnerability in the FTP daemon on MikroTik routers through 6.44.3 could allow remote attackers to exhaust all available memory, causing the device to reboot because of uncontrolled resource management. |
| CVE-2019-3924 | HIGH | 7.5 | Feb 20, 2019 | MikroTik RouterOS before 6.43.12 (stable) and 6.42.12 (long-term) is vulnerable to an intermediary vulnerability. The software will execute user defined network requests to both WAN and LAN clients. A remote unauthenticated attacker can use this vulnerability to bypass the router's firewall or for general network scanning activities. |
| CVE-2025-6443 | HIGH | 7.2 | Jun 25, 2025 | Mikrotik RouterOS VXLAN Source IP Improper Access Control Vulnerability. This vulnerability allows remote attackers to bypass access restrictions on affected installations of Mikrotik RouterOS. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of remote IP addresses when processing VXLAN traffic. The issue results from the lack of validation of the remote IP address against configured values prior to allowing ingress traffic into the inte |
| CVE-2022-36522 | MEDIUM | 6.5 | Aug 26, 2022 | Mikrotik RouterOs through stable v6.48.3 was discovered to contain an assertion failure in the component /advanced-tools/nova/bin/netwatch. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted packet. |
Showing the 20 most severe of 47 known CVEs.
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