diff --git a/lldb/include/lldb/Host/FileSystem.h b/lldb/include/lldb/Host/FileSystem.h
--- a/lldb/include/lldb/Host/FileSystem.h
+++ b/lldb/include/lldb/Host/FileSystem.h
@@ -189,6 +189,9 @@
   void Collect(const FileSpec &file_spec);
   void Collect(const llvm::Twine &file);
 
+  bool ReadableByCurrentUser(const FileSpec &file_spec) const;
+  bool ReadableByCurrentUser(const llvm::Twine &file) const;
+
 private:
   static llvm::Optional<FileSystem> &InstanceImpl();
   llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> m_fs;
diff --git a/lldb/source/Commands/CommandObjectTarget.cpp b/lldb/source/Commands/CommandObjectTarget.cpp
--- a/lldb/source/Commands/CommandObjectTarget.cpp
+++ b/lldb/source/Commands/CommandObjectTarget.cpp
@@ -277,9 +277,10 @@
         result.SetStatus(eReturnStatusFailed);
         return false;
       }
-      if (!FileSystem::Instance().Readable(core_file)) {
-        result.AppendErrorWithFormat("core file '%s' is not readable",
-                                     core_file.GetPath().c_str());
+      if (!FileSystem::Instance().ReadableByCurrentUser(core_file)) {
+        result.AppendErrorWithFormat(
+            "core file '%s' is not readable by the current user.",
+            core_file.GetPath().c_str());
         result.SetStatus(eReturnStatusFailed);
         return false;
       }
@@ -289,9 +290,10 @@
       FileSpec symfile(m_symbol_file.GetOptionValue().GetCurrentValue());
       if (symfile) {
         if (FileSystem::Instance().Exists(symfile)) {
-          if (!FileSystem::Instance().Readable(symfile)) {
-            result.AppendErrorWithFormat("symbol file '%s' is not readable",
-                                         symfile.GetPath().c_str());
+          if (!FileSystem::Instance().ReadableByCurrentUser(symfile)) {
+            result.AppendErrorWithFormat(
+                "symbol file '%s' is not readable by the current user.",
+                symfile.GetPath().c_str());
             result.SetStatus(eReturnStatusFailed);
             return false;
           }
diff --git a/lldb/source/Host/common/FileSystem.cpp b/lldb/source/Host/common/FileSystem.cpp
--- a/lldb/source/Host/common/FileSystem.cpp
+++ b/lldb/source/Host/common/FileSystem.cpp
@@ -7,6 +7,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "lldb/Host/FileSystem.h"
+#include "lldb/Host/File.h"
+#include "lldb/Host/HostInfo.h"
 
 #include "lldb/Utility/LLDBAssert.h"
 #include "lldb/Utility/TildeExpressionResolver.h"
@@ -491,3 +493,13 @@
     m_collector->addFile(file);
   }
 }
+
+bool FileSystem::ReadableByCurrentUser(const FileSpec &file_spec) const {
+  return Readable(file_spec) &&
+         Instance().Open(file_spec, File::eOpenOptionRead);
+}
+
+bool FileSystem::ReadableByCurrentUser(const llvm::Twine &file_path) const {
+  FileSpec file(file_path.getSingleStringRef());
+  return Readable(file_path) && Instance().Open(file, File::eOpenOptionRead);
+}
diff --git a/lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp b/lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
--- a/lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
+++ b/lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
@@ -91,20 +91,17 @@
     // Resolve any executable within a bundle on MacOSX
     Host::ResolveExecutableInBundle(resolved_module_spec.GetFileSpec());
 
-    if (FileSystem::Instance().Exists(resolved_module_spec.GetFileSpec()))
+    if (!FileSystem::Instance().Exists(resolved_module_spec.GetFileSpec()))
+      error.SetErrorStringWithFormat(
+          "unable to find executable for '%s'",
+          resolved_module_spec.GetFileSpec().GetPath().c_str());
+    else if (!FileSystem::Instance().ReadableByCurrentUser(
+                 resolved_module_spec.GetFileSpec())) {
+      error.SetErrorStringWithFormat(
+          "executable '%s' is not readable by the current user",
+          resolved_module_spec.GetFileSpec().GetPath().c_str());
+    } else
       error.Clear();
-    else {
-      const uint32_t permissions = FileSystem::Instance().GetPermissions(
-          resolved_module_spec.GetFileSpec());
-      if (permissions && (permissions & eFilePermissionsEveryoneR) == 0)
-        error.SetErrorStringWithFormat(
-            "executable '%s' is not readable",
-            resolved_module_spec.GetFileSpec().GetPath().c_str());
-      else
-        error.SetErrorStringWithFormat(
-            "unable to find executable for '%s'",
-            resolved_module_spec.GetFileSpec().GetPath().c_str());
-    }
   } else {
     if (m_remote_platform_sp) {
       error =
@@ -188,7 +185,7 @@
       }
 
       if (error.Fail() || !exe_module_sp) {
-        if (FileSystem::Instance().Readable(
+        if (FileSystem::Instance().ReadableByCurrentUser(
                 resolved_module_spec.GetFileSpec())) {
           error.SetErrorStringWithFormat(
               "'%s' doesn't contain any '%s' platform architectures: %s",
@@ -196,7 +193,7 @@
               GetPluginName().GetCString(), arch_names.GetData());
         } else {
           error.SetErrorStringWithFormat(
-              "'%s' is not readable",
+              "'%s' is not readable by the current user",
               resolved_module_spec.GetFileSpec().GetPath().c_str());
         }
       }
diff --git a/lldb/test/API/commands/target/basic/TestTargetCommand.py b/lldb/test/API/commands/target/basic/TestTargetCommand.py
--- a/lldb/test/API/commands/target/basic/TestTargetCommand.py
+++ b/lldb/test/API/commands/target/basic/TestTargetCommand.py
@@ -337,6 +337,12 @@
         self.expect("target create -c '" + tf.name + "'", error=True,
                     substrs=["core file '", "' is not readable"])
 
+    @skipIfWindows
+    @no_debug_info_test
+    def test_target_create_unowned_core_file(self):
+        self.expect("target create -c ~root", error=True,
+                    substrs=["core file '", "' is not readable"])
+
     @no_debug_info_test
     def test_target_create_nonexistent_sym_file(self):
         self.expect("target create -s doesntexist doesntexisteither", error=True,