/ 
perl-5.41.3
⭐ Starred 2013
/ ExtUtils::Mkbootstrap
Security Advisories (1)
CVE-2025-40909 (2025-05-30)

Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6

NAME

ExtUtils::Mkbootstrap - make a bootstrap file for use by DynaLoader

SYNOPSIS

Mkbootstrap

DESCRIPTION

Mkbootstrap typically gets called from an extension Makefile.

There is no *.bs file supplied with the extension. Instead, there may be a *_BS file which has code for the special cases, like posix for berkeley db on the NeXT.

This file will get parsed, and produce a maybe empty @DynaLoader::dl_resolve_using array for the current architecture. That will be extended by $BSLOADLIBS, which was computed by ExtUtils::Liblist::ext(). If this array still is empty, we do nothing, else we write a .bs file with an @DynaLoader::dl_resolve_using array.

The *_BS file can put some code into the generated *.bs file by placing it in $bscode. This is a handy 'escape' mechanism that may prove useful in complex situations.

If @DynaLoader::dl_resolve_using contains -L* or -l* entries then Mkbootstrap will automatically add a dl_findfile() call to the generated *.bs file.