You should check the capabilities of the container, if it has any of the following ones, you might be able to scape from it:
CAP_SYS_ADMIN
CAP_SYS_PTRACE
CAP_SYS_MODULE
DAC_READ_SEARCH
DAC_OVERRIDE
CAP_SYS_RAWIO
CAP_SYSLOG
CAP_NET_RAW
CAP_NET_ADMIN
You can check currently container capabilities using
capsh --print