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HighCISA KEVExploited in the wildPublic exploit

Command Injection in D-Link DIR-823X /goform/set_prohibiting

IdentifiersCVE-2025-29635CWE-78

CVE-2025-29635 is a command injection vulnerability affecting D-Link DIR-823X routers, including firmware versions 240126 and 240802/24082 as referenced in the provided content. The flaw is reachable through the router management interface via crafted POST requests to the /goform/set_prohibiting endpoint. According to the supplied analysis, attacker-controlled input is copied into a shell command string using snprintf() and then executed via system() without proper sanitization or validation. Researchers specifically noted that the vulnerable code path allows shell metacharacter injection, resulting in arbitrary operating system command execution on the device. The issue has been observed in active exploitation by Mirai operators deploying the tuxnokill variant to compromised 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 enables remote execution of arbitrary OS commands on the affected router. In observed attacks, adversaries used the flaw to download and execute shell scripts and install Mirai malware, conscripting devices into a DDoS botnet. More broadly, compromise of the router can enable persistent backdoor installation, traffic interception, configuration tampering, use of the device as a pivot point for lateral movement, and disruption of network availability through botnet-driven DDoS activity.

Mitigation

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

If immediate replacement or patching is not possible, restrict or disable access to the router management interface, especially from the internet; disable remote administration if not strictly required; limit administrative access to trusted internal networks or IP allowlists; change default or weak administrator credentials; monitor for unexpected configuration changes and suspicious outbound connections; and isolate vulnerable devices from sensitive internal segments. Because active exploitation by Mirai has been reported, internet-exposed end-of-life devices should be treated as high risk and prioritized for removal or containment.

Remediation

Patch, then assume compromise.

Apply a vendor firmware update that addresses CVE-2025-29635 if one is available for the affected DIR-823X build. However, the provided content repeatedly states that the affected DIR-823X devices are legacy/end-of-life and may not receive a fix; in that case, the appropriate remediation is replacement with a supported router model. Organizations should inventory exposed DIR-823X devices, remove unsupported units from service, and verify that no compromised scripts, binaries, or unauthorized configuration changes remain on replaced or retained devices.
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-LinkDir-823xhardware
D-LinkDir-823x Firmwareoperating_system

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

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware15

Malware families riding this exploit, with evidence and IOCs.

Detection signatures2

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 activity38

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