cbcvebase.
CVE-2025-9533
published 2025-08-27

CVE-2025-9533: A vulnerability has been found in TOTOLINK T10 4.1.8cu.5241_B20210927. Affected is an unknown function of the file /formLoginAuth.htm. The manipulation of the…

PriorityP272critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
9.21%
94.8th percentile
A vulnerability has been found in TOTOLINK T10 4.1.8cu.5241_B20210927. Affected is an unknown function of the file /formLoginAuth.htm. The manipulation of the argument authCode with the input 1 leads to improper authentication. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.

Affected

2 ranges
VendorProductVersion rangeFixed in
totolinkt10——
totolinkt10_firmware——

Detection & IOCsextracted from sources · hover to see the quote

path/formLoginAuth.htm↗
url/formLoginAuth.htm?authCode=1↗
snort
alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS Totolink formLoginAuth.htm authCode Parameter Authentication Bypass Attempt (CVE-2025-9533)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/formLoginAuth.htm|3f|"; startswith; fast_pattern; content:"authCode|3d|1"; reference:url,github.com/aLtEr6/MY_test/blob/main/TOTOLINK/TOTOLINK%20T10%20Vulnerability.md; reference:cve,2025-9533; classtype:attempted-admin; sid:2064179; rev:1; metadata:affected_product TOTOLINK, attack_target Networking_Equipment, tls_state plaintext, created_at 2025_08_27, cve CVE_2025_9533, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_08_27, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)
  • →Look for HTTP GET requests targeting /formLoginAuth.htm with the query parameter authCode=1 (URL-encoded: authCode%3d1). This specific value triggers authentication bypass on TOTOLINK T10 devices. ↗
  • →The attack is plaintext HTTP (tls_state plaintext), making it fully visible to perimeter and internal network inspection without TLS decryption.
  • →MITRE mapping: TA0001 Initial Access / T1190 Exploit Public-Facing Application. Prioritize detection on internet-exposed TOTOLINK T10 networking equipment.
  • →The Snort/ET rule uses sid:2064179 (rev:1, classtype:attempted-admin). Ensure this SID is enabled in Suricata/Snort deployments at the network perimeter and internally.
  • ·Affected version is specifically TOTOLINK T10 firmware 4.1.8cu.5241_B20210927. Verify firmware version before applying detection rules to avoid false positives on unaffected devices. ↗
  • ·The exploit has been publicly disclosed; a PoC is available at the referenced GitHub repository, meaning exploitation in the wild is plausible and detection should be treated as high priority. ↗

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv4.05.5MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.