CVE-2021-27790

Root code execution via ipfilter stack overflow

Published Aug 12, 2021 · Updated Aug 3, 2024

Stack overflow in Brocade Fabric OS before 9.0.1a, 8.2.3, 8.2.0_CBN4, and 7.4.2h allows local users to execute code as root. The ipfilter command passes user input to an unsafe string function without enforcing the destination stack buffer's bounds. An authenticated CLI session and access to ipfilter are required; successful exploitation grants root control of the switch.

CVSS severity7.8
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack overflow in Brocade Fabric OS before 9.0.1a, 8.2.3, 8.2.0_CBN4, and 7.4.2h allows local users to execute code as root. The ipfilter command passes user input to an unsafe string function without enforcing the destination stack buffer's bounds. An authenticated CLI session and access to ipfilter are required; successful exploitation grants root control of the switch.

The record

CVE
CVE-2021-27790
Published
Aug 12, 2021
Updated
Aug 3, 2024
Vendor
Brocade Communications Systems
Product
Brocade Fabric OS
Classifications
CWE-787, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Brocade Fabric OS before Brocade Fabric OS v.9.0.1a, v8.2.3, and v8.2.0_CBN4, and v7.4.2h

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Brocade Communications Systems · Brocade Fabric OSversion=Brocade Fabric OS before Brocade Fabric OS v.9.0.1a, v8.2.3, and v8.2.0_CBN4, and v7.4.2h

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
7.8BroadcomCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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