Cannot fetch data: remote error: tls: illegal parameter.

[sgtserge]

Hi all,

starting from some days ago, which could coincide with zabbix agent upgrade to 7.0.17, I started to get this error on a item using zabbix agent and "web.certificate.get" when trying to get SSL certificate details from a site.




I took a look to zabbix agent logs in verbose mode but I didn't find anything usefull

2025/08/22 07:54:42.052083 failed to execute direct exporter task for key 'web.certificate.get[[mysite]]' error: 'Cannot fetch data: remote error: tls: illegal parameter.'

Doing a curl or a openssl trace gives this error

curl: (35) OpenSSL/3.0.13: error:0A000152:SSL routines::unsafe legacy renegotiation disabled

Looking around I found that it could be realted to secure renegotiation not supported on server side, as explained here: https://stackoverflow.com/questions/...ation-disabled

Adding the "UnsafeLegacyRenegotiation" parameter in the openssl.cfg works, but still in zabbix agent I get the same error.

Anybody has any clue on how to tell zabbix agent to use the same parameter when fetching SSL certs data?

Thank you

Sergio

[sgtserge]

UPDATE: downgrading agent to 7.0.13 it works, so must be some change in new versions of zabbix agent

[rvbochs]

I have the same issue after upgrading agent version to 7.0.17.

[sgtserge]

UPDATE: i resoloved unsafe legacy renegotiation errors but error "illegal parameter" still persists.

I can confirm that with Zabbix agent 7.0.13 all is working as expected. Once upgrading to 7.0.14 i get the above error.