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CriticalCISA KEVExploited in the wildPublic exploit

Unauthenticated Command Injection in D-Link DSL-2750B login.cgi

IdentifiersCVE-2016-20017CWE-78

CVE-2016-20017 is an unauthenticated OS command injection vulnerability affecting D-Link DSL-2750B devices before firmware version 1.05. The flaw is exposed through the web management interface, specifically the /login.cgi endpoint via the cli parameter. An attacker can send a crafted HTTP request containing shell metacharacters or injected commands in that parameter, causing the device to execute arbitrary commands at the operating-system level without prior authentication. Reporting in the provided content indicates the issue was exploited in the wild from at least 2016 through 2022, including use by botnet operators targeting legacy D-Link DSL gateway routers.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows remote unauthenticated execution of arbitrary system commands on the affected router. In practice, this can enable full compromise of the device, including malware installation, botnet enrollment, configuration manipulation, traffic interception or redirection, persistence, and use of the router as infrastructure for further attacks. Because the target is an edge network device, compromise can also affect availability and confidentiality for downstream network users.

Mitigation

If you can’t patch tonight, do this now.

If immediate remediation is not possible, restrict access to the router’s web administration interface to trusted internal management networks only, disable WAN/Internet-facing administration, and apply network ACLs or firewall rules to block untrusted access to HTTP/HTTPS management endpoints. Monitor for suspicious requests to /login.cgi, especially those referencing the cli parameter, and for signs of post-compromise activity such as unexpected outbound connections, malware downloads, or configuration changes. Given documented in-the-wild exploitation, unsupported internet-exposed devices should be treated as high risk and isolated or replaced.

Remediation

Patch, then assume compromise.

Upgrade affected D-Link DSL-2750B devices to firmware version 1.05 or later, as the vulnerability affects versions before 1.05. If vendor-supported fixed firmware is not available for a deployed unit, replace the device with a supported model. Confirm that remote management exposure is minimized after upgrade and validate that the web interface no longer accepts command-injection payloads via the vulnerable parameter.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
D-LinkDsl-2750b Firmwareoperating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

9 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

9 SOURCESView more in app
What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware2

Malware families riding this exploit, with evidence and IOCs.

Detection signatures1

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity7

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES
MITRE CVE
cve.org · CVE-2016-20017
NVD
nvd.nist.gov/vuln/detail/CVE-2016-20017
MITRE CWE · CWE-78
cwe.mitre.org
Patch
supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10088
Third Party Advisory
seclists.org/fulldisclosure/2016/Feb/53
Third Party Advisory
exploit-db.com/exploits/44760
US Government Resource
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2016-20017