Small Business Srp521wHardware / appliance · Cisco

CVE-2011-4005

HIGH · 9.3 CVSS v2.0 Published 2011-11-03

Fix available

A fix is available. Upgrade to after 1.02.01_mr2 or later.

See remediation →

100/100

Remediation priority · Urgent

Remotely reachable No privileges Zero-click

Official description

NVD · unedited

Cross-site request forgery (CSRF) vulnerability in the Services Ready Platform Configuration Utility web interface on the Cisco Small Business SRP521W, SRP526W, and SRP527W with firmware before 1.1.24 and the Small Business SRP541W, SRP546W, and SRP547W with firmware before 1.2.1 allows remote attackers to hijack the authentication of administrators for requests that execute arbitrary commands, aka Bug ID CSCtr45124.

Technical summary

dbcve analysis · high confidence

Cross-site request forgery (CSRF) vulnerability in the Cisco Small Business SRP500 and SRP540 series routers' web interface allows remote attackers to hijack administrator sessions and execute arbitrary commands. The vulnerability affects SRP521W, SRP526W, SRP527W (firmware < 1.1.24) and SRP541W, SRP546W, SRP547W (firmware < 1.2.1).

MitigationUpgrade firmware to version 1.1.24 (SRP500 series) or 1.2.1 (SRP540 series) or later to patch the CSRF vulnerability. As a compensating control, restrict administrative web interface access to trusted networks only.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

Small Business Srp521wHardware / appliance

Affected:all versions

Small Business Srp526wHardware / appliance

Affected:all versions

Small Business Srp527wHardware / appliance

Affected:all versions

Small Business Srp520 Series FirmwareApplication

Affected:<= 1.01.23= 1.00.06= 1.01.01= 1.01.19_mr3

Small Business Srp541wHardware / appliance

Affected:all versions

Small Business Srp546wHardware / appliance

Affected:all versions

Small Business Srp547wHardware / appliance

Affected:all versions

Small Business Srp540 Series FirmwareApplication

Affected:<= 1.02.01_mr2= 1.02.00

CVSS breakdown

From the vector

Attack vector: Network
Complexity: M
Authentication: None
Confidentiality: Complete
Integrity: Complete
Availability: Complete

AV:N/AC:M/Au:N/C:C/I:C/A:C

Am I affected?

dbcve checks

Work through these to decide whether this CVE applies to you.

Identify the router model

Access the router web interface or CLI and retrieve the model number. Look for SRP521W, SRP526W, SRP527W, SRP541W, SRP546W, or SRP547W identifiers in the device status or label.

Affected if The model is any of the affected SRP500 or SRP540 series routers.
Check the installed firmware version

Log into the router web interface and navigate to the status or administration page to view the firmware version. Alternatively, use the CLI command 'show version' or check the firmware file name if upgraded manually.

Affected if For SRP527W models: firmware version is lower than 1.1.24. For SRP541W/546W/547W models: firmware version is lower than 1.2.1. For SRP520 series: version is 1.01.23 or lower, or exactly 1.00.06, 1.01.01, or 1.01.19_mr3. For SRP540 series: version is 1.02.01_mr2 or lower, or exactly 1.02.00.
Verify the web interface is accessible

Attempt to access the router web interface over HTTP/HTTPS from a remote host using the configured IP address. Check if the login page responds.

Affected if The web management interface is exposed and reachable from network segments where attackers could send CSRF requests.
Confirm administrative access method

Check the router configuration for web interface access settings. Verify whether HTTP/HTTPS administrative access is enabled and on which interfaces (LAN/WAN).

Affected if Administrative web access is enabled on any interface, particularly if accessible from WAN.

The environment is affected if the device is an SRP500 or SRP540 series model running firmware below the fixed versions (1.1.24 for SRP500 series, 1.2.1 for SRP540 series) and the web interface is accessible.

Generated from the published advisory. Verify against your own configuration.

Remediation

dbcve · scoped

Upgrade available Upgrade to a release after 1.02.01_mr2

Interim mitigation

Upgrade firmware to version 1.1.24 (SRP500 series) or 1.2.1 (SRP540 series) or later to patch the CSRF vulnerability. As a compensating control, restrict administrative web interface access to trusted networks only.

Recommended fix High confidence

Firmware 1.1.24 for SRP521W/526W/527W series; Firmware 1.2.1 or later for SRP541W/546W/547W series

1. Identify the specific Cisco Small Business SRP model (521W, 526W, 527W, 541W, 546W, or 547W) from the device label or web interface.
2. Access the Cisco support portal or official firmware download page for the Small Business SRP series.
3. Download the appropriate firmware version: for SRP521W/526W/527W download version 1.1.24 or later; for SRP541W/546W/547W download version 1.2.1 or later.
4. Log in to the device web interface as administrator.
5. Navigate to the Administration or System Settings section to locate the firmware upgrade option.
6. Upload the downloaded firmware file and initiate the upgrade process.
7. Wait for the device to reboot and verify the new firmware version is installed.
8. After upgrade, clear browser session cookies and re-authenticate to ensure no stale sessions remain.

Caveat Firmware upgrades on network devices may cause temporary service disruption; ensure proper power supply and backup configuration before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Small Business Srp521w Scoped from the published advisory

Consultation4.0 h
Implementation3.0 h
Testing4.0 h
Review / QA2.0 h

13.0 hours of engineering $2,300

Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,680.

Scan for this in your stack

Free · runs locally

dbcve dependency scanner

Check whether your project pulls in CVE-2011-4005 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2011-4005 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2011-4005?

The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.

The version that genuinely resolved it — not the one the vendor claimed
A config change or rule that shut the vector down
A gotcha in the upgrade path that cost you an afternoon

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here

Verified mitigations, workarounds, and config changes
Version or environment caveats, and links to real fixes
No weaponised exploit code, or anything meant to cause harm
No spam, self-promotion, credentials, or personal data

At a glance

A fix existsUpgrade to after 1.02.01_mr2 or later

Severity 9.3 High

Exploit likelihood EPSS, next 30 days 1.8%

Affects: Small Business Srp521w

Remediation

A high-priority fix

Fix this in Small Business Srp521w 13 hrs · Moderate

Typical engagement from $2,300

Get a fix See the full breakdown ↓

A high-priority vulnerability. Send your environment and a specialist will scope CVE-2011-4005 and return a fixed quote and timeline.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

Check your environment

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References