PPPd crashes with fatal signal 6 on 2.4.7 version

[Arsalan19]

PPPd crashes with fatal signal 6 on 2.4.7 version soon after receiving a CHAP challenge request from the server.
Corefile is not generated as this is packaged on a cisco device. Issue is only seen when using CHAP authentication.

pppd[4459]: Fatal signal 6

[paulusmack]

Version 2.4.7 is nearly 10 years old, and if this is packaged on a cisco device then the source may have been modified by Cisco.

If you can reproduce with the current source or with unmodified version 2.5.0, then we can take a look at it, otherwise we will need to reject this issue.

[Arsalan19]

Cisco is using unmodified 2.4.7 code base. This is packaged on cisco sdwan device. The server used here is Mikrotik router and the cisco device is the ppp client. On disabling the mschap1 and mschap2 authentication and having just PAP and CHAP authentication enabled on the Mikrotik router (PPP server) resolves the issue and pppoe session is being formed with the server. On re-enabling the mschap1 and mschap2 also resolves the issue. I'm not sure if the issue is with the server or the client. im not aware of the pppd version used on the server. Could this be an inter-operability issue? Can you suggest how i can debug this issue?