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HighPublic exploit

OS Command Injection in Totolink A7100RU setWiFiGuestCfg

IdentifiersCVE-2026-5993CWE-78· Improper Neutralization of Special…

CVE-2026-5993 is an OS command injection vulnerability affecting Totolink A7100RU firmware version 7.4cu.2313_b20191024. The flaw is present in the CGI Handler component, specifically in the setWiFiGuestCfg function exposed through /cgi-bin/cstecgi.cgi. According to the provided content, improper handling of the wifiOff argument allows attacker-controlled input to reach an operating system command context without sufficient sanitization or neutralization. A remote attacker can exploit this issue by sending crafted requests to the vulnerable CGI endpoint, resulting in command injection on the underlying system.

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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 can allow a remote attacker to execute arbitrary operating system commands on the affected device. Based on the provided severity information, the vulnerability can result in high impact to confidentiality, integrity, and availability, enabling full compromise of the router, unauthorized modification of configuration or system state, disclosure of sensitive information, and potential service disruption.

Mitigation

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

If a fixed firmware version is not yet available, restrict network access to the device management interface and specifically to /cgi-bin/cstecgi.cgi to trusted administrative hosts only. Disable remote administration if not required, place the device management plane behind internal-only access controls, and monitor for suspicious requests targeting setWiFiGuestCfg or containing shell metacharacters in the wifiOff parameter. Because a public exploit is reported as available, exposure of the management interface to untrusted networks should be treated as high risk.

Remediation

Patch, then assume compromise.

Upgrade Totolink A7100RU to a vendor-fixed firmware release if one is available. The vulnerable firmware identified in the provided content is version 7.4cu.2313_b20191024. Remediation should include correcting input handling in setWiFiGuestCfg within /cgi-bin/cstecgi.cgi so that the wifiOff parameter cannot influence shell command execution, preferably by avoiding shell invocation entirely and using safe parameterized APIs or strict allowlist validation.
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
TotolinkA7100ruhardware
TotolinkA7100ru Firmwareoperating_system

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

ACTIVITY FEED

Recent activity

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

4 SOURCESView more in app
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 malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

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 activity3

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

EXTERNAL REFERENCES
MITRE CVE
cve.org · CVE-2026-5993
NVD
nvd.nist.gov/vuln/detail/CVE-2026-5993
MITRE CWE · CWE-78
Improper Neutralization of Special Elements…
github.com
github.com/Litengzheng/vuldb_new/blob/main/A7100RU/vul_165/README.md
vuldb.com
vuldb.com/submit/792041
vuldb.com
vuldb.com/vuln/356547
vuldb.com
vuldb.com/vuln/356547/cti
totolink.net
totolink.net