LoFP LoFP / t1499

t1499

TitleTags
a misconfgured network application or firewall may trigger this alert. security scans or test cycles may trigger this alert.
legitimate acme certificate renewal agents (cert-manager, certbot, caddy) use acme-tls/1 during tls-alpn-01 challenges. a single incomplete challenge due to a network timeout can occur normally, but five or more incomplete sessions from the same source within the detection window is abnormal even for misconfigured acme clients. tls decode_error or illegal_parameter alerts can also be produced by buggy tls clients or misconfigured load balancers. suppress by adding known acme client source ips or acme ca validation ip ranges to an exception list.
legitimate causes such as system maintenance, server shutdowns, or temporary network outages may trigger this alert.
serious issues with a configuration or plugin
system updates, scheduled backups, or misconfigured services may trigger this alert.
unknown
unlikely