CVE-2019-19825Public exploitNetwork attack vector

CAPTCHA bypass via plaintext login response

Published Jan 27, 2020 · Updated Aug 5, 2024

Improper authentication in affected TOTOLINK router firmware allows remote attackers to retrieve CAPTCHA text through the login endpoint. The Boa formLogin handler accepts an unauthenticated setting/getSanvas request and returns the current CAPTCHA value in plaintext. Administration-interface access and valid credentials remain required for router actions, but the disclosure enables automated login attempts on A3002RU 2.0.0 and earlier, A702R 2.1.3 and earlier, N301RT 2.1.6 and earlier, N302R, N300RT, N150RT, and N100RE 3.4.0 and earlier, and N200RE 4.0.0 and earlier.

CVSS severity9.8
Critical
EPSS probability29.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in affected TOTOLINK router firmware allows remote attackers to retrieve CAPTCHA text through the login endpoint. The Boa formLogin handler accepts an unauthenticated setting/getSanvas request and returns the current CAPTCHA value in plaintext. Administration-interface access and valid credentials remain required for router actions, but the disclosure enables automated login attempts on A3002RU 2.0.0 and earlier, A702R 2.1.3 and earlier, N301RT 2.1.6 and earlier, N302R, N300RT, N150RT, and N100RE 3.4.0 and earlier, and N200RE 4.0.0 and earlier.

The record

CVE
CVE-2019-19825
Published
Jan 27, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-804, CWE-287, T1110.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 27, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-804Guessable CAPTCHA
CWE-287Improper Authentication
T1110.001Brute Force: Password Guessing

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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