D-Link DIR-2640 HNAP LoginPassword Authentication Bypass Vulnerability
D-Link DIR-2640 HNAP LoginPassword Authentication Bypass Vulnerability. This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of D-Link DIR-2640 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the web management interface, which listens on TCP port 80 by default. A specially crafted login request can cause authentication to succeed without providing proper credentials. An attacker can leverage this vulnerability to bypass authentication on the system. . Was ZDI-CAN-19549.
- Published
- May 2, 2024
- Updated
- Jun 17, 2026
- EPSS
- 28.9% · 98th percentile
- CWE
- CWE-303
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Report tools
Action score
35
Monitor
Low priority for now.
- CVSS
- 26 / 40 · 6.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 9 / 30 · 28.9%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · zdi
- 6.5
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| dlink | dir-2640 firmware | cpe:2.3:o:dlink:dir-2640_firmware |
| dlink | dir-2640 | cpe:2.3:h:dlink:dir-2640 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- dlink dir-2640 firmware1.11b02
Versions reported by the vendor
Affected version ranges reported by the assigning authority (zdi). Independent of NVD's CPE analysis and usually ahead of it.
D-Link DIR-2640
- 1.11B02 (non-US, CA version)affected
Same product
dlink: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-5293D-Link DIR-2640 HTTP Referer Stack-Based Buffer Overflow Remote Code Execution Vulnerability35Monitor
- CVE-2023-32149D-Link DIR-2640 prog.cgi Request Handling Stack-based Buffer Overflow Remote Code Execution Vulnerability35Monitor
- CVE-2023-32148D-Link DIR-2640 HNAP PrivateLogin Authentication Bypass Vulnerability35Monitor
- CVE-2023-32153D-Link DIR-2640 EmailFrom Command Injection Remote Code Execution Vulnerability34Monitor
- CVE-2023-32150D-Link DIR-2640 PrefixLen Command Injection Remote Code Execution Vulnerability34Monitor
- CVE-2023-32151D-Link DIR-2640 DestNetwork Command Injection Remote Code Execution Vulnerability28Monitor
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.
- CVE-2023-321480 days apartD-Link DIR-2640 HNAP PrivateLogin Authentication Bypass Vulnerability35Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
- CVE-2023-321500 days apartD-Link DIR-2640 PrefixLen Command Injection Remote Code Execution Vulnerability34Monitor
- CVE-2023-321530 days apartD-Link DIR-2640 EmailFrom Command Injection Remote Code Execution Vulnerability34Monitor
- CVE-2023-321470 days apartD-Link DIR-2640 LocalIPAddress Command Injection Remote Code Execution Vulnerability28Monitor
- CVE-2023-321510 days apartD-Link DIR-2640 DestNetwork Command Injection Remote Code Execution Vulnerability28Monitor
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone on the same network segment 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
- none
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Adjacent
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-303 · Incorrect Implementation of Authentication AlgorithmCVSS vector
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
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.
References
- supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10323
- www.zerodayinitiative.com/advisories/ZDI-23-544/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.