diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/SessionDescription.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/SessionDescription.java
index f6f12513d..62424e81f 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/SessionDescription.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/SessionDescription.java
@@ -3,6 +3,7 @@ package eu.siacs.conversations.xmpp.jingle;
 import android.util.Log;
 import android.util.Pair;
 
+import com.google.common.base.CharMatcher;
 import com.google.common.base.Joiner;
 import com.google.common.base.Strings;
 import com.google.common.collect.ArrayListMultimap;
@@ -131,6 +132,8 @@ public class SessionDescription {
         final ImmutableList.Builder<Media> mediaListBuilder = new ImmutableList.Builder<>();
         final Group group = contentMap.group;
         if (group != null) {
+            final String semantics = group.getSemantics();
+            checkNoWhitespace(semantics, "group semantics value must not contain any whitespace");
             attributeMap.put("group", group.getSemantics() + " " + Joiner.on(' ').join(group.getIdentificationTags()));
         }
 
@@ -150,9 +153,11 @@ public class SessionDescription {
             if (!Strings.isNullOrEmpty(ufrag)) {
                 mediaAttributes.put("ice-ufrag", ufrag);
             }
+            checkNoWhitespace(ufrag, "ufrag value must not contain any whitespaces");
             if (!Strings.isNullOrEmpty(pwd)) {
                 mediaAttributes.put("ice-pwd", pwd);
             }
+            checkNoWhitespace(pwd, "pwd value must not contain any whitespaces");
             mediaAttributes.put("ice-options", HARDCODED_ICE_OPTIONS);
             final IceUdpTransportInfo.Fingerprint fingerprint = transport.getFingerprint();
             if (fingerprint != null) {
@@ -180,6 +185,7 @@ public class SessionDescription {
                     if (Strings.isNullOrEmpty(type)) {
                         throw new IllegalArgumentException("a feedback for payload-type " + id + " negotiation is missing type");
                     }
+                    checkNoWhitespace(type, "feedback negotiation type must not contain whitespace");
                     mediaAttributes.put("rtcp-fb", id + " " + type + (Strings.isNullOrEmpty(subtype) ? "" : " " + subtype));
                 }
                 for (RtpDescription.FeedbackNegotiationTrrInt feedbackNegotiationTrrInt : payloadType.feedbackNegotiationTrrInts()) {
@@ -193,6 +199,7 @@ public class SessionDescription {
                 if (Strings.isNullOrEmpty(type)) {
                     throw new IllegalArgumentException("a feedback negotiation is missing type");
                 }
+                checkNoWhitespace(type, "feedback negotiation type must not contain whitespace");
                 mediaAttributes.put("rtcp-fb", "* " + type + (Strings.isNullOrEmpty(subtype) ? "" : " " + subtype));
             }
             for (RtpDescription.FeedbackNegotiationTrrInt feedbackNegotiationTrrInt : description.feedbackNegotiationTrrInts()) {
@@ -204,9 +211,11 @@ public class SessionDescription {
                 if (Strings.isNullOrEmpty(id)) {
                     throw new IllegalArgumentException("A header extension is missing id");
                 }
+                checkNoWhitespace(id, "header extension id must not contain whitespace");
                 if (Strings.isNullOrEmpty(uri)) {
                     throw new IllegalArgumentException("A header extension is missing uri");
                 }
+                checkNoWhitespace(uri, "feedback negotiation uri must not contain whitespace");
                 mediaAttributes.put("extmap", id + " " + uri);
             }
             for (RtpDescription.SourceGroup sourceGroup : description.getSourceGroups()) {
@@ -215,6 +224,7 @@ public class SessionDescription {
                 if (Strings.isNullOrEmpty(semantics)) {
                     throw new IllegalArgumentException("A SSRC group is missing semantics attribute");
                 }
+                checkNoWhitespace(semantics, "source group semantics must not contain whitespace");
                 if (groups.size() == 0) {
                     throw new IllegalArgumentException("A SSRC group is missing SSRC ids");
                 }
@@ -228,13 +238,14 @@ public class SessionDescription {
                     if (Strings.isNullOrEmpty(id)) {
                         throw new IllegalArgumentException("A source specific media attribute is missing the id");
                     }
+                    checkNoWhitespace(id, "A source specific media attributes must not contain whitespaces");
                     if (Strings.isNullOrEmpty(parameterName)) {
                         throw new IllegalArgumentException("A source specific media attribute is missing its name");
                     }
                     if (Strings.isNullOrEmpty(parameterValue)) {
                         throw new IllegalArgumentException("A source specific media attribute is missing its value");
                     }
-                    mediaAttributes.put("ssrc", id + " " + parameter.getParameterName() + ":" + parameter.getParameterValue());
+                    mediaAttributes.put("ssrc", id + " " + parameterName + ":" + parameterValue);
                 }
             }
 
@@ -263,6 +274,13 @@ public class SessionDescription {
         return sessionDescriptionBuilder.createSessionDescription();
     }
 
+    public static String checkNoWhitespace(final String input, final String message) {
+        if (CharMatcher.whitespace().matchesAnyOf(input)) {
+            throw new IllegalArgumentException(message);
+        }
+        return input;
+    }
+
     public static int ignorantIntParser(final String input) {
         try {
             return Integer.parseInt(input);
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/stanzas/RtpDescription.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/stanzas/RtpDescription.java
index 00b2ddc60..5f1a76af9 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/stanzas/RtpDescription.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/stanzas/RtpDescription.java
@@ -232,7 +232,10 @@ public class RtpDescription extends GenericDescription {
 
         public String toSdpAttribute() {
             final int channels = getChannels();
-            return getId()+" "+getPayloadTypeName()+"/"+getClockRate()+(channels == 1 ? "" : "/"+channels);
+            final String name = getPayloadTypeName();
+            Preconditions.checkArgument(name != null, "Payload-type name must not be empty");
+            SessionDescription.checkNoWhitespace(name, "payload-type name must not contain whitespaces");
+            return getId()+" "+name+"/"+getClockRate()+(channels == 1 ? "" : "/"+channels);
         }
 
         public int getIntId() {
@@ -367,7 +370,15 @@ public class RtpDescription extends GenericDescription {
             stringBuilder.append(id).append(' ');
             for(int i = 0; i < parameters.size(); ++i) {
                 Parameter p = parameters.get(i);
-                stringBuilder.append(p.getParameterName()).append('=').append(p.getParameterValue());
+                final String name = p.getParameterName();
+                Preconditions.checkArgument(name != null, String.format("parameter for %s must have a name", id));
+                SessionDescription.checkNoWhitespace(name, String.format("parameter names for %s must not contain whitespaces", id));
+
+                final String value = p.getParameterValue();
+                Preconditions.checkArgument(value != null, String.format("parameter for %s must have a value", id));
+                SessionDescription.checkNoWhitespace(value, String.format("parameter values for %s must not contain whitespaces", id));
+
+                stringBuilder.append(name).append('=').append(value);
                 if (i != parameters.size() - 1) {
                     stringBuilder.append(';');
                 }