treewide: Fix unsafe concatenation of $LD_LIBRARY_PATH

Naive concatenation of $LD_LIBRARY_PATH can result in an empty
colon-delimited segment; this tells glibc to load libraries from the
current directory, which is definitely wrong, and may be a security
vulnerability if the current directory is untrusted.  (See #67234, for
example.)  Fix this throughout the tree.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

1 files changed, 2 insertions, 2 deletions

diff --git a/pkgs/development/libraries/jsoncpp/default.nix b/pkgs/development/libraries/jsoncpp/default.nix
index 72158e186ac2..7b06cc8ad4e6 100644
--- a/pkgs/development/libraries/jsoncpp/default.nix
+++ b/pkgs/development/libraries/jsoncpp/default.nix
@@ -23,9 +23,9 @@ stdenv.mkDerivation rec {
   # Hack to be able to run the test, broken because we use
   # CMAKE_SKIP_BUILD_RPATH to avoid cmake resetting rpath on install
   preBuild = if stdenv.isDarwin then ''
-    export DYLD_LIBRARY_PATH="`pwd`/src/lib_json:$DYLD_LIBRARY_PATH"
+    export DYLD_LIBRARY_PATH="`pwd`/src/lib_json''${DYLD_LIBRARY_PATH:+:}$DYLD_LIBRARY_PATH"
   '' else ''
-    export LD_LIBRARY_PATH="`pwd`/src/lib_json:$LD_LIBRARY_PATH"
+    export LD_LIBRARY_PATH="`pwd`/src/lib_json''${LD_LIBRARY_PATH:+:}$LD_LIBRARY_PATH"
   '';
 
   nativeBuildInputs = [ cmake python ];