diff --git a/Crashlytics/CHANGELOG.md b/Crashlytics/CHANGELOG.md
index 59058cf574c..598aed30656 100644
--- a/Crashlytics/CHANGELOG.md
+++ b/Crashlytics/CHANGELOG.md
@@ -1,5 +1,6 @@
 # Unreleased
 - [fixed] Updated `upload-symbols` to version 3.20, wait for `debug.dylib` DWARF content getting generated when build with `--build-phase` option. Added `debug.dylib` DWARF content to run script input file list for user who enabled user script sandboxing (#14054).
+- [fixed] Updated all memory allocation from `malloc()` to `calloc()` (#14209).
 
 # 11.5.0
 - [changed] Updated `upload-symbols` to version 3.19, removed all methods require CFRelease and switch to modern classes (#13420).
diff --git a/Crashlytics/Crashlytics/Components/FIRCLSBinaryImage.m b/Crashlytics/Crashlytics/Components/FIRCLSBinaryImage.m
index 35cb32b02fb..c7e1a602e83 100644
--- a/Crashlytics/Crashlytics/Components/FIRCLSBinaryImage.m
+++ b/Crashlytics/Crashlytics/Components/FIRCLSBinaryImage.m
@@ -409,7 +409,7 @@ static void FIRCLSBinaryImageChanged(bool added,
   // fill imageDetails fields using slice & vmaddr_slide
   FIRCLSBinaryImageFillInImageDetails(&imageDetails);
 
-  FIRCLSImageChange* change = malloc(sizeof(FIRCLSImageChange));
+  FIRCLSImageChange* change = calloc(1, sizeof(FIRCLSImageChange));
   if (!change) return;
   change->added = added;
   change->details = imageDetails;
diff --git a/Crashlytics/Crashlytics/Helpers/FIRCLSAllocate.c b/Crashlytics/Crashlytics/Helpers/FIRCLSAllocate.c
index 206b9a4e80d..acf78d98496 100644
--- a/Crashlytics/Crashlytics/Helpers/FIRCLSAllocate.c
+++ b/Crashlytics/Crashlytics/Helpers/FIRCLSAllocate.c
@@ -175,7 +175,7 @@ void* FIRCLSAllocatorSafeAllocateFromRegion(FIRCLSAllocationRegion* region, size
     // this shouldn't happen unless we make a mistake with our size pre-computations
     if ((uintptr_t)originalCursor - (uintptr_t)region->start + size > region->size) {
       FIRCLSSDKLog("Unable to allocate sufficient memory, falling back to malloc\n");
-      void* ptr = malloc(size);
+      void* ptr = calloc(1, size);
       if (!ptr) {
         FIRCLSSDKLog("Unable to malloc in FIRCLSAllocatorSafeAllocateFromRegion\n");
         return NULL;
@@ -197,7 +197,7 @@ void* FIRCLSAllocatorSafeAllocate(FIRCLSAllocatorRef allocator,
   if (!allocator) {
     // fall back to malloc in this case
     FIRCLSSDKLog("Allocator invalid, falling back to malloc\n");
-    void* ptr = malloc(size);
+    void* ptr = calloc(1, size);
     if (!ptr) {
       FIRCLSSDKLog("Unable to malloc in FIRCLSAllocatorSafeAllocate\n");
       return NULL;
@@ -207,7 +207,7 @@ void* FIRCLSAllocatorSafeAllocate(FIRCLSAllocatorRef allocator,
 
   if (allocator->protectionEnabled) {
     FIRCLSSDKLog("Allocator already protected, falling back to malloc\n");
-    void* ptr = malloc(size);
+    void* ptr = calloc(1, size);
     if (!ptr) {
       FIRCLSSDKLog("Unable to malloc in FIRCLSAllocatorSafeAllocate\n");
       return NULL;
diff --git a/Crashlytics/Crashlytics/Helpers/FIRCLSFile.m b/Crashlytics/Crashlytics/Helpers/FIRCLSFile.m
index 204782a633b..1f4d2a0c836 100644
--- a/Crashlytics/Crashlytics/Helpers/FIRCLSFile.m
+++ b/Crashlytics/Crashlytics/Helpers/FIRCLSFile.m
@@ -74,7 +74,7 @@ static bool FIRCLSFileInit(
 
   file->bufferWrites = bufferWrites;
   if (bufferWrites) {
-    file->writeBuffer = malloc(FIRCLSWriteBufferLength * sizeof(char));
+    file->writeBuffer = calloc(1, FIRCLSWriteBufferLength * sizeof(char));
     if (!file->writeBuffer) {
       FIRCLSErrorLog(@"Unable to malloc in FIRCLSFileInit");
       return false;
@@ -668,7 +668,7 @@ void FIRCLSFileWriteArrayEntryHexEncodedString(FIRCLSFile* file, const char* val
 
 NSString* FIRCLSFileHexEncodeString(const char* string) {
   size_t length = strlen(string);
-  char* encodedBuffer = malloc(length * 2 + 1);
+  char* encodedBuffer = calloc(1, length * 2 + 1);
 
   if (!encodedBuffer) {
     FIRCLSErrorLog(@"Unable to malloc in FIRCLSFileHexEncodeString");
@@ -693,7 +693,7 @@ void FIRCLSFileWriteArrayEntryHexEncodedString(FIRCLSFile* file, const char* val
 
 NSString* FIRCLSFileHexDecodeString(const char* string) {
   size_t length = strlen(string);
-  char* decodedBuffer = malloc(length);  // too long, but safe
+  char* decodedBuffer = calloc(1, length);  // too long, but safe
   if (!decodedBuffer) {
     FIRCLSErrorLog(@"Unable to malloc in FIRCLSFileHexDecodeString");
     return nil;
diff --git a/Crashlytics/Crashlytics/Helpers/FIRCLSUtility.m b/Crashlytics/Crashlytics/Helpers/FIRCLSUtility.m
index 7592aa01424..21e87ac66fd 100644
--- a/Crashlytics/Crashlytics/Helpers/FIRCLSUtility.m
+++ b/Crashlytics/Crashlytics/Helpers/FIRCLSUtility.m
@@ -185,7 +185,7 @@ void FIRCLSRedactUUID(char* value) {
   // null terminator
   length = [data length];
   size = (length * 2) + 1;
-  buffer = malloc(sizeof(char) * size);
+  buffer = calloc(1, sizeof(char) * size);
 
   if (!buffer) {
     FIRCLSErrorLog(@"Unable to malloc in FIRCLSNSDataToNSString");
diff --git a/Crashlytics/Crashlytics/Models/Record/FIRCLSReportAdapter.m b/Crashlytics/Crashlytics/Models/Record/FIRCLSReportAdapter.m
index 900f93c20ee..543c6bfc718 100644
--- a/Crashlytics/Crashlytics/Models/Record/FIRCLSReportAdapter.m
+++ b/Crashlytics/Crashlytics/Models/Record/FIRCLSReportAdapter.m
@@ -171,7 +171,7 @@ - (google_crashlytics_FilesPayload)protoFilesPayload {
 
   NSArray<NSString *> *clsRecords = [self clsRecordFilePaths];
   google_crashlytics_FilesPayload_File *files =
-      malloc(sizeof(google_crashlytics_FilesPayload_File) * clsRecords.count);
+      calloc(1, sizeof(google_crashlytics_FilesPayload_File) * clsRecords.count);
 
   if (files == NULL) {
     // files and files_count are initialized to NULL and 0 by default.
@@ -271,7 +271,7 @@ - (google_crashlytics_Platforms)protoPlatformFromString:(NSString *)str {
   // For bytes, it is just a strict memeory copy of the data in NSData.
   // The whole structure will be freed as a part of process for deallocing report in dealloc() of
   // this class
-  pb_bytes_array_t *pbBytes = malloc(PB_BYTES_ARRAY_T_ALLOCSIZE(data.length));
+  pb_bytes_array_t *pbBytes = calloc(1, PB_BYTES_ARRAY_T_ALLOCSIZE(data.length));
   if (pbBytes == NULL) {
     return NULL;
   }
diff --git a/Crashlytics/Shared/FIRCLSByteUtility.m b/Crashlytics/Shared/FIRCLSByteUtility.m
index 8298bf1299c..f27d60be7a3 100644
--- a/Crashlytics/Shared/FIRCLSByteUtility.m
+++ b/Crashlytics/Shared/FIRCLSByteUtility.m
@@ -58,7 +58,7 @@ void FIRCLSSafeHexToString(const uint8_t *value, size_t length, char *outputBuff
   // null terminator
   length = data.length;
   size = (length * 2) + 1;
-  buffer = malloc(sizeof(char) * size);
+  buffer = calloc(1, sizeof(char) * size);
 
   if (!buffer) {
     return nil;
diff --git a/Crashlytics/Shared/FIRCLSMachO/FIRCLSMachOBinary.m b/Crashlytics/Shared/FIRCLSMachO/FIRCLSMachOBinary.m
index 02e9125af74..2b8b67915a3 100644
--- a/Crashlytics/Shared/FIRCLSMachO/FIRCLSMachOBinary.m
+++ b/Crashlytics/Shared/FIRCLSMachO/FIRCLSMachOBinary.m
@@ -144,7 +144,7 @@ static void FIRCLSSafeHexToString(const uint8_t* value, size_t length, char* out
   // null terminator
   length = [data length];
   size = (length * 2) + 1;
-  buffer = malloc(sizeof(char) * size);
+  buffer = calloc(1, sizeof(char) * size);
 
   if (!buffer) {
     return nil;
diff --git a/Crashlytics/UnitTests/FIRCLSCompactUnwindTests.m b/Crashlytics/UnitTests/FIRCLSCompactUnwindTests.m
index 204911949b2..fc5bcabf73a 100644
--- a/Crashlytics/UnitTests/FIRCLSCompactUnwindTests.m
+++ b/Crashlytics/UnitTests/FIRCLSCompactUnwindTests.m
@@ -33,7 +33,7 @@ @implementation FIRCLSCompactUnwindTests
 - (void)setUp {
   [super setUp];
 
-  _firclsContext.readonly = malloc(sizeof(FIRCLSReadOnlyContext));
+  _firclsContext.readonly = calloc(1, sizeof(FIRCLSReadOnlyContext));
   _firclsContext.readonly->logPath = "/tmp/test.log";
 }
 
diff --git a/Crashlytics/UnitTests/FIRCLSDwarfTests.m b/Crashlytics/UnitTests/FIRCLSDwarfTests.m
index 4dfb98d1c2d..7a97afa1abb 100644
--- a/Crashlytics/UnitTests/FIRCLSDwarfTests.m
+++ b/Crashlytics/UnitTests/FIRCLSDwarfTests.m
@@ -33,7 +33,7 @@ @implementation FIRCLSDwarfTests
 - (void)setUp {
   [super setUp];
 
-  _firclsContext.readonly = malloc(sizeof(FIRCLSReadOnlyContext));
+  _firclsContext.readonly = calloc(1, sizeof(FIRCLSReadOnlyContext));
   _firclsContext.readonly->logPath = "/tmp/test.log";
 }
 
diff --git a/Crashlytics/UnitTests/FIRCLSFileTests.m b/Crashlytics/UnitTests/FIRCLSFileTests.m
index b8895f68a67..09e3ba2428c 100644
--- a/Crashlytics/UnitTests/FIRCLSFileTests.m
+++ b/Crashlytics/UnitTests/FIRCLSFileTests.m
@@ -217,7 +217,7 @@ - (void)hexEncodingLongStringWithFile:(FIRCLSFile *)file
                              filePath:(NSString *)filePath
                                length:(size_t)length
                              buffered:(BOOL)buffered {
-  char *longString = malloc(length * sizeof(char));
+  char *longString = calloc(1, length * sizeof(char));
 
   memset(longString, 'a', length);  // fill it with 'a' characters
   longString[length - 1] = 0;       // null terminate
@@ -432,7 +432,7 @@ - (void)closeAndOpenAlternatingBufferedOptionWithFile:(FIRCLSFile *)file
 
 - (void)testLoggingInputLongerThanBuffer {
   size_t inputLength = (FIRCLSWriteBufferLength + 2) * sizeof(char);
-  char *input = malloc(inputLength);
+  char *input = calloc(1, inputLength);
   for (size_t i = 0; i < inputLength - 1; i++) {
     input[i] = i % 26 + 'a';
   }
diff --git a/Crashlytics/UnitTests/FIRCLSLoggingTests.m b/Crashlytics/UnitTests/FIRCLSLoggingTests.m
index b79341fe06e..475d8c79bdb 100644
--- a/Crashlytics/UnitTests/FIRCLSLoggingTests.m
+++ b/Crashlytics/UnitTests/FIRCLSLoggingTests.m
@@ -302,7 +302,7 @@ - (void)testUserLogNil {
 
 - (void)testLargeLogLine {
   size_t strLength = 100 * 1024;  // Attempt to write 100k of data
-  char* longLine = malloc(strLength + 1);
+  char* longLine = calloc(1, strLength + 1);
   memset(longLine, 'a', strLength);
   longLine[strLength] = '\0';
   NSString* longStr = [[NSString alloc] initWithBytesNoCopy:longLine