CVE-2017-5135
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 · uneditedCertain Technicolor devices have an SNMP access-control bypass, possibly involving an ISP customization in some cases. The Technicolor (formerly Cisco) DPC3928SL with firmware D3928SL-P15-13-A386-c3420r55105-160127a could be reached by any SNMP community string from the Internet; also, you can write in the MIB because it provides write properties, aka Stringbleed. NOTE: the string-bleed/StringBleed-CVE-2017-5135 GitHub repository is not a valid reference as of 2017-04-27; it contains Trojan horse code purported to exploit this vulnerability.
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 · high confidenceThe Technicolor DPC3928SL DSL modem has a critical SNMP authentication bypass vulnerability where the device accepts any SNMP community string from the Internet instead of enforcing the configured community string. Additionally, the device provides write access to the MIB, allowing an attacker to modify SNMP values remotely without proper authentication.
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= d3928sl-p15-13-a386-c3420r55105-160127aCVSS 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
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
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 device modelCheck the device label or login to the router admin interface to confirm the model is Technicolor DPC3928SLAffected if The device is a Technicolor DPC3928SL DSL modem
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Check if SNMP UDP port 161 is exposed to the InternetUse an online port scanner or run 'nmap -p 161 -Pn <your-public-ip>' from an external network to test if UDP port 161 is reachable from the InternetAffected if UDP port 161 is open and reachable from the Internet
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Test SNMP authentication bypassFrom an external network, use 'snmpwalk -v2c -c public <public-ip> system' or try any community string. If any string returns SNMP data without rejection, the vulnerability is presentAffected if SNMP responds to arbitrary community strings from external IPs without authentication failure
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Verify firmware versionLogin to the router admin interface and check the firmware version under status or system settings, or use 'snmpget' to query the device if SNMP is accessibleAffected if Firmware version matches d3928sl-p15-13-a386-c3420r55105-160127a or is an earlier unreleased version
The device is affected if it is a Technicolor DPC3928SL with SNMP UDP port 161 exposed to the Internet and the firmware matches the affected version.
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.
From vendor dataImmediately block SNMP (UDP port 161) from the Internet at the network perimeter. If available, apply vendor firmware updates. If SNMP is required for management, implement IP-based access controls and use strong, non-default community strings.
- Consultation4.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2017-5135 — 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-2017-5135 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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