From: Otto Moerbeek <otto.moerbeek@open-xchange.com>
Date: Tue, 22 Sep 2020 11:19:21 +0000 (+0200)
Subject: Backport essential part of #9497 to rec-4.3.x
X-Git-Tag: rec-4.3.5~3^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F9507%2Fhead;p=thirdparty%2Fpdns.git

Backport essential part of #9497 to rec-4.3.x
---

diff --git a/pdns/dnsparser.cc b/pdns/dnsparser.cc
index 0fd335edba..e39a58cf16 100644
--- a/pdns/dnsparser.cc
+++ b/pdns/dnsparser.cc
@@ -50,7 +50,9 @@ public:
     out.reserve(total+1);
     for(unsigned int n=0; n < total; ++n) {
       int c;
-      sscanf(relevant.c_str()+2*n, "%02x", &c);
+      if (sscanf(&relevant.at(2*n), "%02x", &c) != 1) {
+        throw MOADNSException("unable to read data at position " + std::to_string(2 * n) + " from unknown record of size " + std::to_string(relevant.size()));
+      }
       out.append(1, (char)c);
     }