Sg250x 24 FirmwareOperating system · Cisco
CVE-2020-3297
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.
NVD · uneditedA vulnerability in session management for the web-based interface of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to defeat authentication protections and gain unauthorized access to the management interface. The attacker could obtain the privileges of the highjacked session account, which could include administrator privileges on the device. The vulnerability is due to the use of weak entropy generation for session identifier values. An attacker could exploit this vulnerability to determine a current session identifier through brute force and reuse that session identifier to take over an ongoing session. In this way, an attacker could take actions within the management interface with privileges up to the level of the administrative user.
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.
dbcve analysis · moderate confidenceThe vulnerability exists in the session management of Cisco Small Business Switch web interfaces where session identifiers are generated using weak entropy, making them predictable through brute force. An unauthenticated attacker can enumerate valid session IDs and reuse them to hijack active sessions, potentially gaining full administrator privileges on the device.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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.
NVD · CPE data
Sg250x 24 FirmwareOperating system
< 2.5.5.47
Sg250x 24p FirmwareOperating system
< 2.5.5.47
Sg250x 48 FirmwareOperating system
< 2.5.5.47
Sg250x 48p FirmwareOperating system
< 2.5.5.47
Sg250 08 FirmwareOperating system
< 2.5.5.47
Sg250 08hp FirmwareOperating system
< 2.5.5.47
Sg250 10p FirmwareOperating system
< 2.5.5.47
Sg250 18 FirmwareOperating system
< 2.5.5.47CVSS 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.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the switch modelAccess the device CLI or web interface and record the exact model number (e.g., SG250-18, SG250x-48p)Affected if The model is one of: SG250x 24, SG250x 24p, SG250x 48, SG250x 48p, SG250 08, SG250 08hp, SG250 10p, or SG250 18
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Check the firmware versionIn the web interface go to Administration > Firmware or use CLI command 'show version'Affected if The firmware version is lower than 2.5.5.47
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Verify the web management interface is enabledIn the web interface go to Administration > Management Interface > HTTP/HTTPS Settings, or use CLI 'show http server'Affected if HTTP or HTTPS web management is enabled (the vulnerability applies to the session handling of active sessions)
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Confirm active session handling is in useLog into the web interface and observe that a session cookie or session ID is created upon authenticationAffected if Users authenticate via the web interface (the vulnerability allows session ID prediction for active sessions)
A defender is affected if they use any of the listed SG250 switch models with firmware version below 2.5.5.47 and have the web management interface enabled.
Generated from the published advisory. Verify against your own configuration.
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.
dbcve · scoped2.5.5.47
Apply the Cisco firmware patch when available; until then, restrict web management interface access to trusted networks only and monitor for suspicious session activity.
Firmware version 2.5.5.47 or later for SG250 series switches
- 1. Back up the current switch configuration to a secure location before upgrading.
- 2. Download the firmware version 2.5.5.47 or later from the Cisco software download center (software.cisco.com) for your specific SG250 model.
- 3. Verify the integrity of the downloaded firmware file using checksums provided by Cisco.
- 4. Access the switch web-based management interface or use Cisco's configuration tool to upload the new firmware.
- 5. During the firmware upload process, ensure continuous power to the switch - do not interrupt the upgrade.
- 6. After the upgrade completes, the switch will reboot automatically.
- 7. Once the switch restarts, log in and verify that the firmware version has been updated to 2.5.5.47 or later.
- 8. Restore the previously backed-up configuration to the switch.
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Sg250x 24 Firmware
Scoped from the published advisory
- Consultation4.0 h
- Implementation3.0 h
- Testing4.0 h
- Review / QA2.0 h
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 locallyCheck whether your project pulls in CVE-2020-3297 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-3297 in production — separate from our analysis above.
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
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- Version or environment caveats, and links to real fixes
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