diff --git a/src/feature/dircache/consdiffmgr.c b/src/feature/dircache/consdiffmgr.c
index bf3a0ef3cf..2cddf68b69 100644
--- a/src/feature/dircache/consdiffmgr.c
+++ b/src/feature/dircache/consdiffmgr.c
@@ -189,6 +189,7 @@ static consdiff_cfg_t consdiff_cfg = {
 
 static int consdiffmgr_ensure_space_for_files(int n);
 static int consensus_queue_compression_work(const char *consensus,
+                                            size_t consensus_len,
                                             const networkstatus_t *as_parsed);
 static int consensus_diff_queue_diff_work(consensus_cache_entry_t *diff_from,
                                           consensus_cache_entry_t *diff_to);
@@ -509,8 +510,25 @@ get_max_age_to_cache(void)
                                         MAX_MAX_AGE_TO_CACHE);
 }
 
+#ifdef TOR_UNIT_TESTS
+/** As consdiffmgr_add_consensus, but requires a nul-terminated input. For
+ * testing. */
+int
+consdiffmgr_add_consensus_nulterm(const char *consensus,
+                                  const networkstatus_t *as_parsed)
+{
+  size_t len = strlen(consensus);
+  /* make a non-nul-terminated copy so that we can have a better chance
+   * of catching errors. */
+  char *ctmp = tor_memdup(consensus, len);
+  int r = consdiffmgr_add_consensus(ctmp, len, as_parsed);
+  tor_free(ctmp);
+  return r;
+}
+#endif
+
 /**
- * Given a string containing a networkstatus consensus, and the results of
+ * Given a buffer containing a networkstatus consensus, and the results of
  * having parsed that consensus, add that consensus to the cache if it is not
  * already present and not too old.  Create new consensus diffs from or to
  * that consensus as appropriate.
@@ -519,6 +537,7 @@ get_max_age_to_cache(void)
  */
 int
 consdiffmgr_add_consensus(const char *consensus,
+                          size_t consensus_len,
                           const networkstatus_t *as_parsed)
 {
   if (BUG(consensus == NULL) || BUG(as_parsed == NULL))
@@ -544,7 +563,7 @@ consdiffmgr_add_consensus(const char *consensus,
   }
 
   /* We don't have it. Add it to the cache. */
-  return consensus_queue_compression_work(consensus, as_parsed);
+  return consensus_queue_compression_work(consensus, consensus_len, as_parsed);
 }
 
 /**
@@ -1826,14 +1845,15 @@ static int background_compression = 0;
  */
 static int
 consensus_queue_compression_work(const char *consensus,
+                                 size_t consensus_len,
                                  const networkstatus_t *as_parsed)
 {
   tor_assert(consensus);
   tor_assert(as_parsed);
 
   consensus_compress_worker_job_t *job = tor_malloc_zero(sizeof(*job));
-  job->consensus = tor_strdup(consensus);
-  job->consensus_len = strlen(consensus);
+  job->consensus = tor_memdup_nulterm(consensus, consensus_len);
+  job->consensus_len = strlen(job->consensus);
   job->flavor = as_parsed->flavor;
 
   char va_str[ISO_TIME_LEN+1];
diff --git a/src/feature/dircache/consdiffmgr.h b/src/feature/dircache/consdiffmgr.h
index d6f273cc4e..011c8799d6 100644
--- a/src/feature/dircache/consdiffmgr.h
+++ b/src/feature/dircache/consdiffmgr.h
@@ -22,6 +22,7 @@ typedef struct consdiff_cfg_t {
 struct consensus_cache_entry_t; // from conscache.h
 
 int consdiffmgr_add_consensus(const char *consensus,
+                              size_t consensus_len,
                               const networkstatus_t *as_parsed);
 
 consdiff_status_t consdiffmgr_find_consensus(
@@ -73,4 +74,9 @@ STATIC int uncompress_or_set_ptr(const char **out, size_t *outlen,
                                  consensus_cache_entry_t *ent);
 #endif /* defined(CONSDIFFMGR_PRIVATE) */
 
+#ifdef TOR_UNIT_TESTS
+int consdiffmgr_add_consensus_nulterm(const char *consensus,
+                                      const networkstatus_t *as_parsed);
+#endif
+
 #endif /* !defined(TOR_CONSDIFFMGR_H) */
diff --git a/src/feature/dircache/dirserv.c b/src/feature/dircache/dirserv.c
index b85db8324f..433d3f4ce4 100644
--- a/src/feature/dircache/dirserv.c
+++ b/src/feature/dircache/dirserv.c
@@ -1272,6 +1272,7 @@ free_cached_dir_(void *_d)
  * validation is performed. */
 void
 dirserv_set_cached_consensus_networkstatus(const char *networkstatus,
+                                           size_t networkstatus_len,
                                            const char *flavor_name,
                                            const common_digests_t *digests,
                                            const uint8_t *sha3_as_signed,
@@ -1282,7 +1283,9 @@ dirserv_set_cached_consensus_networkstatus(const char *networkstatus,
   if (!cached_consensuses)
     cached_consensuses = strmap_new();
 
-  new_networkstatus = new_cached_dir(tor_strdup(networkstatus), published);
+  new_networkstatus =
+    new_cached_dir(tor_memdup_nulterm(networkstatus, networkstatus_len),
+                   published);
   memcpy(&new_networkstatus->digests, digests, sizeof(common_digests_t));
   memcpy(&new_networkstatus->digest_sha3_as_signed, sha3_as_signed,
          DIGEST256_LEN);
diff --git a/src/feature/dircache/dirserv.h b/src/feature/dircache/dirserv.h
index 9be4bf9db2..c430987aa7 100644
--- a/src/feature/dircache/dirserv.h
+++ b/src/feature/dircache/dirserv.h
@@ -148,6 +148,7 @@ int directory_too_idle_to_fetch_descriptors(const or_options_t *options,
 
 cached_dir_t *dirserv_get_consensus(const char *flavor_name);
 void dirserv_set_cached_consensus_networkstatus(const char *consensus,
+                                              size_t consensus_len,
                                               const char *flavor_name,
                                               const common_digests_t *digests,
                                               const uint8_t *sha3_as_signed,
diff --git a/src/feature/nodelist/networkstatus.c b/src/feature/nodelist/networkstatus.c
index 847ca0cdfc..97a8779bea 100644
--- a/src/feature/nodelist/networkstatus.c
+++ b/src/feature/nodelist/networkstatus.c
@@ -2107,17 +2107,18 @@ networkstatus_set_current_consensus(const char *consensus,
 
   if (we_want_to_fetch_flavor(options, flav)) {
     dirserv_set_cached_consensus_networkstatus(consensus,
+                                               consensus_len,
                                                flavor,
                                                &c->digests,
                                                c->digest_sha3_as_signed,
                                                c->valid_after);
     if (dir_server_mode(get_options())) {
-      consdiffmgr_add_consensus(consensus, c);
+      consdiffmgr_add_consensus(consensus, consensus_len, c);
     }
   }
 
   if (!from_cache) {
-    write_str_to_file(consensus_fname, consensus, 0);
+    write_bytes_to_file(consensus_fname, consensus, consensus_len, 0);
   }
 
   warn_early_consensus(c, flavor, now);
diff --git a/src/test/test_consdiffmgr.c b/src/test/test_consdiffmgr.c
index 4b49fdb6aa..966314be13 100644
--- a/src/test/test_consdiffmgr.c
+++ b/src/test/test_consdiffmgr.c
@@ -21,6 +21,8 @@
 #include "test/test.h"
 #include "test/log_test_helpers.h"
 
+#define consdiffmgr_add_consensus consdiffmgr_add_consensus_nulterm
+
 static char *
 consensus_diff_apply_(const char *c, const char *d)
 {
diff --git a/src/test/test_dir_handle_get.c b/src/test/test_dir_handle_get.c
index ecb7c1b5fc..b591396913 100644
--- a/src/test/test_dir_handle_get.c
+++ b/src/test/test_dir_handle_get.c
@@ -67,6 +67,8 @@ ENABLE_GCC_WARNING(overlength-strings)
 #define NOT_ENOUGH_CONSENSUS_SIGNATURES "HTTP/1.0 404 " \
   "Consensus not signed by sufficient number of requested authorities\r\n\r\n"
 
+#define consdiffmgr_add_consensus consdiffmgr_add_consensus_nulterm
+
 static dir_connection_t *
 new_dir_conn(void)
 {