CVE-2025-45488: Linksys E5600 v1.1.0.26 was discovered to contain a command injection vulnerability in the runtime.ddnsStatus DynDNS function via the mailex parameter.

PriorityP268critical9.8CVSS 3.1

AVNACLPRNUINSUCHIHAH

EPSS

11.09%

95.8th percentile

Linksys E5600 v1.1.0.26 was discovered to contain a command injection vulnerability in the runtime.ddnsStatus DynDNS function via the mailex parameter.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
linksys	e5600_firmware	—	—

Detection & IOCsextracted from sources · hover to see the quote

urlhttps://github.com/JZP018/vuln03/blob/main/linksys/E5600

path/API/obj

cookie|0d 0a|cookie|0d 0a|

snort

alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS Linksys E5600 runtime.ddnsStatus Multiple Parameters Command Injection Attempt (CVE-2025-45488-2025-45491)"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:8; content:"/API/obj"; http.header_names; to_lowercase; content:"|0d 0a|cookie|0d 0a|"; http.request_body; content:"|22|DdnsP|22|"; fast_pattern; pcre:"/\x22(?:hostname|mailex|username|password).*?(?:(?:\x3b|%3[Bb])|(?:\x0a|%0[Aa])|(?:\x60|%60)|(?:\x7c|%7[Cc])|(?:\x24|%24)|(?:\x26{2}|%26%26))+/"; reference:cve,2025-45488; reference:cve,2025-45489; reference:cve,2025-45490; reference:cve,2025-45491; reference:url,github.com/JZP018/vuln03/blob/main/linksys/E5600; classtype:attempted-admin; sid:2062421; rev:1; metadata:affected_product Linksys, attack_target Networking_Equipment, tls_state plaintext, created_at 2025_05_19, cve CVE_2025_45488, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, updated_at 2025_05_19, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)

bytes

|22|DdnsP|22|

→Exploit targets HTTP POST requests to the exact 8-byte URI /API/obj on the Linksys E5600 device (runtime.ddnsStatus DynDNS function).
→Injection payload is carried in the HTTP request body within the DdnsP JSON object, in one or more of the parameters: hostname, mailex, username, or password.
→Command injection characters to detect in the vulnerable parameters include semicolon (;/%3B), newline (\n/%0A), backtick (`/%60), pipe (|/%7C), dollar sign ($/%24), and double-ampersand (&&/%26%26) — both raw and URL-encoded forms.
→Exploitation is plaintext only (no TLS); deploy detection at the network perimeter and internally facing the device.
→The CVE affects Linksys E5600 v1.1.0.26 specifically; the vulnerable function is runtime.ddnsStatus and the originally reported parameter is mailex. ↗

·The Snort/Suricata rule (sid:2062421) covers four related CVEs (CVE-2025-45488 through CVE-2025-45491) simultaneously; a match does not isolate which specific parameter or CVE is being exploited without further triage of the captured payload.

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