Lets Encrypt certbot failed to authenticate domain with mixed DNS records (AKA do not forget IPv6 records)

Published on April 3rd 2025 - Listed in Internet TLS SSL Security Linux - 0 comments

rsync security update introduced a regression on Debian and Ubuntu Linux (meanwhile fixed)

Published on January 17th 2025 - Listed in Linux Security Backup - 0 comments

Dovecot complaining of missing DH key (Error: Diffie-Hellman key exchange requested, but no DH parameters provided)

Published on September 22nd 2024 - Listed in Linux Mail Security TLS - 0 comments

pure-ftpd: (?@?) [ERROR] Sorry, but that file doesn't exist: [/etc/ssl/private/pure-ftpd.pem]

Published on July 30th 2024 - Listed in Linux TLS Security - 0 comments

fail2ban postfix-sasl filter not working, use postfix auth mode instead

Published on May 31st 2024 - Listed in Monitoring Linux Security Mail - 1 comments

How to fix Zoneminder recorded videos always starting with grey content

Published on May 6th 2024 - Listed in Zoneminder Surveillance Multimedia Security - 0 comments

Unable to open existing JMX config in JMeter (scriptwrapper error)

Published on April 17th 2024 - last updated on April 18th 2024 - Listed in Linux Security - 0 comments

siege [error] socket: unable to connect sock.c:282: Connection refused

Published on February 7th 2024 - Listed in Linux Nginx Apache Security - 0 comments

Cannot open file for writing error while trying to edit a file in /tmp (even as root user)

Published on September 6th 2023 - Listed in Linux Security - 1 comments

How to disable (turn off) LED illuminator lights on Dahua IP surveillance camera

Published on August 25th 2023 - Listed in Hardware Security Network Surveillance - 0 comments

How to renew expired zoneminder repository key (public key is not available: NO_PUBKEY A8C670C86F88B031)

Published on June 14th 2023 - Listed in Linux Surveillance Zoneminder Security - 0 comments

SSH connection not working (userauth_pubkey: key type ssh-rsa not in Pubkey Accepted Algorithms [preauth])

Published on May 16th 2023 - last updated on May 16th 2023 - Listed in Linux Ubuntu Security - 0 comments

Unexpected APT error when trying to enable Ubuntu Pro (ESM) service

Published on May 11th 2023 - Listed in Linux Ubuntu Security SSL TLS - 1 comments

Workaround for negated (exception) iptables rules with multiple sources or destinations

Published on January 30th 2023 - Listed in Network Linux Security - 0 comments

How to solve Citrix Workspace SSL error (You have not chosen to trust...) caused by missing Root CA certificates

Published on December 19th 2022 - last updated on December 20th 2022 - Listed in Linux SSL TLS Security Virtualization - 0 comments

How to manually update the security feeds in GVM (Greenbone Vulnerability Management)

Published on November 29th 2022 - last updated on February 27th 2023 - Listed in Security Linux - 4 comments

How to block a client IP address or range in Cloudflare

Published on November 9th 2022 - Listed in Cloud Security Internet Network - 0 comments

Wordpress (Japanese SEO) hack extracting and executing code from uploaded ZIP file

Published on August 26th 2022 - Listed in Security Wordpress PHP Hacks - 0 comments

Postfix rejects all incoming e-mails with message: blocked using zen.spamhaus.org; Error: open resolver

Published on August 4th 2022 - last updated on August 11th 2022 - Listed in Mail Internet Security Linux - 2 comments

Error: OID not increasing when parsing SNMP output of Checkpoint VSX

Published on July 15th 2022 - Listed in Linux Security Monitoring - 0 comments

Cloudflare managed WAF rule blocks Confluence page edit close request (doeditpage.action)

Published on June 22nd 2022 - Listed in Atlassian Security Internet Cloud - 0 comments

How to detect and fix (mitigate) SSL/TLS renegotiation DOS vulnerability in Postfix

Published on June 20th 2022 - Listed in Mail Internet Security SSL TLS Linux - 0 comments

ILO3 hardware monitoring stopped working after Debian upgrade due to outdated TLS protocols

Published on March 24th 2022 - last updated on July 11th 2024 - Listed in Hardware Monitoring SSL Security - 0 comments

check_http and OpenSSL 1.1.1 - an evil combo due to backward incompatibility with older OpenSSL versions?

Published on March 17th 2022 - last updated on March 23rd 2022 - Listed in TLS SSL Security Monitoring Linux - 0 comments

How to add secure cookie flag on Jira (or any Apache Tomcat) server

Published on March 9th 2022 - Listed in Atlassian Tomcat Security TLS SSL - 0 comments

Handling validity check failed and empty client certificate chain errors in Elasticsearch

Published on March 1st 2022 - last updated on March 7th 2022 - Listed in Elasticsearch ELK Monitoring TLS SSL Security - 0 comments

Technical analysis of Wordpress hack with PHP script lock360.php as running process

Published on February 22nd 2022 - last updated on November 14th 2023 - Listed in PHP Security Linux Hacks Wordpress - 9 comments

New vulnerability exploits lead to mass hack attacks on multiple Wordpress installations

Published on February 18th 2022 - last updated on February 22nd 2022 - Listed in Security Wordpress Internet Hacks - 0 comments

Interface name change in SNMP output after Checkpoint upgrade (R80.30 to R81.10) leads to monitoring issues

Published on January 21st 2022 - Listed in Monitoring Security Network - 0 comments

How to enable missing secure cookie attribute in Roundcube webmail

Published on January 19th 2022 - Listed in Roundcube Cloud Mail Security - 0 comments

SNMP v3 authentication with SHA1 protocol not working after Checkpoint Gaia upgrade to R81.XX

Published on January 18th 2022 - last updated on May 2nd 2022 - Listed in Monitoring Security Network - 2 comments

How to remove a (alternative) domain from a Lets Encrypt (SAN) certificate using certbot

Published on January 17th 2022 - Listed in Security TLS Internet - 0 comments

Using Nginx and LUA script to mitigate against Log4Shell (CVE-2021-44228) vulnerability attacks

Published on December 12th 2021 - last updated on December 15th 2021 - Listed in Nginx Security Internet - 0 comments

Monitoring plugin check_smart 6.12.1 released: Security fix, NVMe perfdata fix, Erase_Fail_Count_Total

Published on December 10th 2021 - last updated on December 10th 2021 - Listed in Hardware Monitoring Security - 0 comments

How to use AWS command line (CLI) with Google Authenticator as virtual MFA device

Published on November 22nd 2021 - Listed in AWS Security Linux Cloud - 0 comments

Lets Encrypt Root CA expiry (server certificate verification failed): Make sure to remove DST Root CA X3!

Published on October 7th 2021 - Listed in Internet TLS Security SSL Linux - 8 comments

Nginx reverse proxy error: SSL alert number 40 while SSL handshaking to upstream server (SSL server name)

Published on August 30th 2021 - Listed in Nginx Security TLS - 8 comments

How to secure the Plesk Panel with a Lets Encrypt certificate (and solve port 8443 problem)

Published on August 24th 2021 - Listed in Internet TLS Security Cloud SSL - 0 comments

Nginx reverse proxy error: SSL alert number 47 while SSL handshaking to upstream

Published on July 14th 2021 - Listed in Nginx Security TLS - 0 comments

APT repository changes its Suite value from stable to oldstable: This must be accepted explicitly before updates for this repository can be applied

Published on July 6th 2021 - last updated on April 22nd 2022 - Listed in Linux Security - 0 comments

How to solve apt error server certificate verification failed

Published on June 4th 2021 - last updated on September 8th 2023 - Listed in Linux TLS Security - 1 comments

Monitoring plugin check_smart 6.9.1 released: Security fix in pseudo-device path

Published on April 8th 2021 - last updated on October 15th 2021 - Listed in Monitoring Hardware Security - 2 comments

After upgrading Linux Mint (Ubuntu), attachments in KeePass 2 do not open anymore: Access denied

Published on March 15th 2021 - Listed in Linux Security - 0 comments

Protect your Wordpress blog from brute force login attacks

Published on February 1st 2021 - last updated on February 2nd 2021 - Listed in Wordpress Security Hacks - 0 comments

Lets Encrypt certbot unable to issue certificate, missing command line (Please choose an account)

Published on January 6th 2021 - Listed in TLS SSL Security Linux - 2 comments

Fixing Perl script using LWP unable to connect to TLS 1.2 URL; failing with sslv3 alert handshake failure

Published on November 2nd 2020 - Listed in Perl Coding Security TLS - 0 comments

Monitoring expiration dates of all ssl/tls certificates in the chain (intermediate and root ca)

Published on June 10th 2020 - Listed in SSL TLS Linux Monitoring Internet Security - 0 comments

Running Harbor registry (Docker repository) behind reverse proxy and solve docker push errors

Published on May 5th 2020 - Listed in Docker Kubernetes Containers Security - 2 comments

How to detect Ghostcat AJP vulnerability (CVE-2020-1938) in Apache Tomcat

Published on April 2nd 2020 - Listed in Security Tomcat Linux Apache - 0 comments

Using ELK to collect Nginx logs and show TLS version and ciphers used by HTTP clients

Published on March 27th 2020 - last updated on June 7th 2024 - Listed in ELK Filebeat Nginx Internet TLS Security - 0 comments

How the X-Cache HTTP header information (HIT, MISS) was abused for targeted attacks on our systems

Published on March 13th 2020 - Listed in Security Internet Varnish Hacks - 4 comments

Windows 10 and Server 2016 clients block access to (Samba) shares with public guest account: Technical analysis and workaround for event 31017

Published on July 22nd 2019 - Listed in Windows Linux Security Samba - 4 comments

Local users becoming root using su without password authentication due to wrong PAM config

Published on July 4th 2019 - Listed in Linux Security - 1 comments

How we successfully deflected a layer 7 DDOS attack with Nginx and GeoIP

Published on June 27th 2019 - Listed in Nginx Internet Security - 0 comments

Debian Wheezy LXC container not running on Stretch host with Kernel 4.18 bpo anymore (a vsyscall story)

Published on May 13th 2019 - last updated on July 2nd 2021 - Listed in Linux LXC Security Containers - 0 comments

Letsencrypt certificate renewal behind http proxy fails with unexpected error: bad handshake

Published on March 18th 2019 - Listed in SSL TLS Security Internet OSSEC - 0 comments

How to manually clean up Zoneminder events (and respect archived events)

Published on December 14th 2018 - last updated on October 17th 2020 - Listed in Zoneminder Surveillance Linux Security - 4 comments

Ignore systemd log warning Failed to reset devices.list: Operation not permitted in OSSEC

Published on July 31st 2018 - Listed in Linux LXC OSSEC Security Systemd - 0 comments

Firmware-Upgrade of a Dahua IPC-HFW1320S network camera

Published on April 18th 2017 - last updated on October 30th 2024 - Listed in Hardware Security Network Surveillance - 1 comments

Allow SSH access based on GeoIP country

Published on November 3rd 2016 - last updated on November 13th 2019 - Listed in Linux Security - 2 comments

Move an iptables firewall rule up the chain before a reject rule

Published on February 4th 2016 - last updated on May 7th 2021 - Listed in Linux Security Network - 0 comments

fatal: Access denied for user by PAM account configuration

Published on July 29th 2015 - Listed in Linux Security - 3 comments

Using Nagios check_smtp -S without SSLv3 (sslv3 alert handshake failure)

Published on October 21st 2014 - Listed in Nagios Monitoring Security Internet Mail - 0 comments

Network Intrusion Detection System with Suricata on Debian Wheezy

Published on October 8th 2014 - Listed in Security Linux Network - 2 comments

Joomla CMS hacks by using vulnerability in com_fabrik

Published on January 26th 2012 - Listed in Internet PHP Hacks Security - 4 comments