# CVE-2019-19825: TOTOLINK - Authentication Bypass

> Live exploitation tracking for CVE-2019-19825 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2019-19825

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** TOTOLINK N150RT
- **Weaknesses:** CWE-287 (Improper Authentication)
- **Tags:** iot

## Description

On certain TOTOLINK Realtek SDK based routers, the CAPTCHA text can be retrieved via an {"topicurl":"setting/getSanvas"} POST to the boafrm/formLogin URI, leading to a CAPTCHA bypass. (Also, the CAPTCHA text is not needed once the attacker has determined valid credentials. The attacker can perform router actions via HTTP requests with Basic Authentication.) This affects A3002RU through 2.0.0, A702R through 2.1.3, N301RT through 2.1.6, N302R through 3.4.0, N300RT through 3.4.0, N200RE through 4.0.0, N150RT through 3.4.0, and N100RE through 3.4.0.

## CrowdSec analysis

[CVE-2019-19825](https://euvd.enisa.europa.eu/vulnerability/CVE-2019-19825) is a critical vulnerability in certain TOTOLINK Realtek SDK-based routers that allows attackers to bypass CAPTCHA protections by retrieving the CAPTCHA text via a crafted POST request. This flaw enables remote attackers to automate login attempts and, once valid credentials are obtained, perform unauthorized router actions through HTTP requests with Basic Authentication. The vulnerability exposes affected devices to risks such as unauthorized configuration changes and potential network compromise.

CrowdSec has been tracking this vulnerability and its exploits since 10th of December 2025.

Data from the CrowdSec community indicates that exploitation of CVE-2019-19825 is highly selective and intelligence-driven. Threat actors use advanced reconnaissance and carefully choose their targets, often as part of sophisticated campaigns or advanced persistent threat operations.
Data from the CrowdSec community also indicates a gradual decrease in attacks targeting CVE-2019-19825. While still present in the wild, exploitation levels have dropped noticeably week-over-week. This may signal that the vulnerability is becoming less relevant or that defenses are improving fast enough for attackers to lose interest.

Attackers exploit the CAPTCHA bypass by sending a POST request with the payload `{"topicurl":"setting/getSanvas"}` to the `/boafrm/formLogin` endpoint on TOTOLINK and Realtek-based routers, allowing them to retrieve the CAPTCHA value and facilitate unauthorized access.

## Timeline

- 2020-01-27: CVE Published. CVE-2019-19825 is published to NVD.
- 2025-12-10: Rule Released. CrowdSec releases a rule to detect CVE-2019-19825 exploitation attempts against the CrowdSec Network.
- 2025-12-15: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2019-19825 for the first time.

## References

- http://packetstormsecurity.com/files/156083/Realtek-SDK-Information-Disclosure-Code-Execution.html
- https://sploit.tech
- http://seclists.org/fulldisclosure/2020/Jan/38
- http://seclists.org/fulldisclosure/2020/Jan/36
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2019/CVE-2019-19825.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2019-19825) follows observed exploitation activity for CVE-2019-19825. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.