vsftpd on TP-Link C2 and C20i devices through firmware 0.9.1 4.2 v0032.0 Build 160706 Rel.37961n has a backdoor admin account with the 1234
vsftpd on TP-Link C2 and C20i devices through firmware 0.9.1 4.2 v0032.0 Build 160706 Rel.37961n has a backdoor admin account with the 1234 password, a backdoor guest account with the guest password, and a backdoor test account with the test password.
- Published
- Apr 25, 2017
- Updated
- Jun 16, 2026
- EPSS
- 2.0% · 80th percentile
- CWE
- CWE-1188
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Report tools
Action score
40
Plan
Add it to your regular patch cycle.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.0%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| tp-link | c2 firmware | cpe:2.3:o:tp-link:c2_firmware |
| tp-link | c2 | cpe:2.3:h:tp-link:c2 |
| tp-link | c20i firmware | cpe:2.3:o:tp-link:c20i_firmware |
| tp-link | c20i | cpe:2.3:h:tp-link:c20i |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- tp-link c2 firmwareup to 0.9.1_4.2_v0032.0_build_160706 inclusive
- tp-link c20i firmwareup to 0.9.1_4.2_v0032.0_build_160706 inclusive
Same product
tp-link: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-8220TP-Link C2 and C20i devices through firmware 0.9.1 4.2 v0032.0 Build 160706 Rel.37961n allow remote code execution with a single HTTP reques50Plan
- CVE-2017-8219TP-Link C2 and C20i devices through firmware 0.9.1 4.2 v0032.0 Build 160706 Rel.37961n allow DoSing the HTTP server via a crafted Cookie hea26Monitor
- CVE-2017-8217TP-Link C2 and C20i devices through firmware 0.9.1 4.2 v0032.0 Build 160706 Rel.37961n have too permissive iptables rules, e.g., SNMP is not21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-1188 · Initialization of a Resource with an Insecure DefaultCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.