The Mikrotik RouterOS web server allows memory corruption in releases before Stable 6.38.5 and Long-term 6.37.5, aka Chimay-Red.

Published 4 y ago 2022-10-15 · modified 4 mo ago 2026-06-17 · JSON

CVSS

9.8

v3.1 · CNA

CISA KEV

not known exploited

EPSS

2.5%

percentile 85%

Public exploits

none known

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.

CISA SSVC assessment

Exploitation: Proof of concept public
Automatable: yes
Technical impact: total
Assessed: 17 mo ago 2025-05-14

Exploit prediction (EPSS)

2.53% probability of exploitation in the next 30 days, higher than 85% of all scored CVEs.

CVSS scores

Assigned by	Version	Score	Vector
CISA ADP	3.1	9.8	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
NVD	3.1	9.8	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
CNA	3.1	9.8	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

Classification

Weakness

CWE-787 Out-of-bounds Write

References

github.com /BigNerd95/Chimay-Red · x_transferred
bleepingcomputer.com /news/security/hajime-botnet-makes-a-comeback-with-massive-scan-for-mikrotik-routers/ · x_transferred

Sources

CVE List: CVE-2017-20149
NVD: CVE-2017-20149

vulnwire keeps one entry per vulnerability: the CVE id wins, then GHSA; records that alias each other are merged. Machine-readable: JSON.