diff --git a/src/main/java/hudson/plugins/cobertura/IOUtils.java b/src/main/java/hudson/plugins/cobertura/IOUtils.java
index 43dfb1a6..cb1ce528 100644
--- a/src/main/java/hudson/plugins/cobertura/IOUtils.java
+++ b/src/main/java/hudson/plugins/cobertura/IOUtils.java
@@ -2,6 +2,11 @@
 
 import java.io.Closeable;
 
+import com.google.common.base.Charsets;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import org.apache.commons.codec.binary.Hex;
+
 /**
  * General IO stream manipulation utilities.
  */
@@ -20,4 +25,23 @@ public static void closeQuietly(Closeable closeable) {
             }
         }
     }
+
+    /**
+     * Sanitizes filename to prevent directory trasversals or other security threats
+     * Transforms every non alphanumeric character in its ascii number in the _XX format
+     *
+     * @param inputName the name to sanitize
+     * @return the sanitized string
+     */
+    public static String sanitizeFilename(String inputName) {
+        Pattern p = Pattern.compile("[^a-zA-Z0-9-]");
+        Matcher m = p.matcher(inputName);
+        StringBuffer sb = new StringBuffer();
+        while (m.find()) {
+            String match = m.group();
+            m.appendReplacement(sb, "_" + Hex.encodeHexString(match.getBytes(Charsets.UTF_8)));
+        }
+        m.appendTail(sb);
+        return sb.toString();
+    }
 }
diff --git a/src/main/java/hudson/plugins/cobertura/renderers/SourceCodePainter.java b/src/main/java/hudson/plugins/cobertura/renderers/SourceCodePainter.java
index 220fd191..41b6b9d9 100644
--- a/src/main/java/hudson/plugins/cobertura/renderers/SourceCodePainter.java
+++ b/src/main/java/hudson/plugins/cobertura/renderers/SourceCodePainter.java
@@ -4,6 +4,7 @@
 
 import hudson.FilePath;
 import hudson.model.TaskListener;
+import hudson.plugins.cobertura.IOUtils;
 import hudson.plugins.cobertura.targets.CoveragePaint;
 import hudson.remoting.VirtualChannel;
 import jenkins.MasterToSlaveFileCallable;
@@ -114,7 +115,7 @@ public void paintSourceCode(File source, CoveragePaint paint, FilePath canvas) t
      * {@inheritDoc}
      */
     public Boolean invoke(File workspaceDir, VirtualChannel channel) throws IOException {
-        final List<File> trialPaths = new ArrayList<File>(sourcePaths.size());
+        final List<File> trialPaths = new ArrayList<>(sourcePaths.size());
         for (String sourcePath : sourcePaths) {
             final File trialPath = new File(sourcePath);
             if (trialPath.exists()) {
@@ -134,7 +135,9 @@ public Boolean invoke(File workspaceDir, VirtualChannel channel) throws IOExcept
             }
             if (source.isFile()) {
                 try {
-                    paintSourceCode(source, entry.getValue(), destination.child(entry.getKey()));
+                    // sanitizing file name to avoid arbitrarily write
+                    String sanitizedName = IOUtils.sanitizeFilename(entry.getKey());
+                    paintSourceCode(source, entry.getValue(), destination.child(sanitizedName));
                 } catch (IOException e) {
                     // We made our best shot at generating painted source code,
                     // but alas, we failed. Log the error and continue. We
diff --git a/src/main/java/hudson/plugins/cobertura/targets/CoverageResult.java b/src/main/java/hudson/plugins/cobertura/targets/CoverageResult.java
index 8511d9ad..231dd70b 100755
--- a/src/main/java/hudson/plugins/cobertura/targets/CoverageResult.java
+++ b/src/main/java/hudson/plugins/cobertura/targets/CoverageResult.java
@@ -8,6 +8,7 @@
 import hudson.plugins.cobertura.Chartable;
 import hudson.plugins.cobertura.CoberturaBuildAction;
 import hudson.plugins.cobertura.CoverageChart;
+import hudson.plugins.cobertura.IOUtils;
 import hudson.plugins.cobertura.Ratio;
 import hudson.util.Graph;
 import hudson.util.TextFile;
@@ -29,6 +30,7 @@
 import java.util.TreeMap;
 import java.util.TreeSet;
 
+import javax.annotation.Nullable;
 import org.jfree.chart.JFreeChart;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.StaplerResponse;
@@ -171,9 +173,16 @@ public void paint(int line, int hits, int branchHits, int branchTotal) {
      *
      * @return The file where the source file should be (if it exists)
      */
+    @Nullable
     private File getSourceFile() {
         if (hasPermission()) {
-            return new File(owner.getParent().getRootDir(), "cobertura/" + relativeSourcePath);
+            File sourceFile = new File(owner.getParent().getRootDir(), "cobertura/" + IOUtils.sanitizeFilename(relativeSourcePath));
+            if (sourceFile.exists()) {
+                return sourceFile;
+            } else {
+                // keep compatibility
+                return new File(owner.getParent().getRootDir(), "cobertura/" + relativeSourcePath);
+            }
         }
         return null;
     }
@@ -185,7 +194,8 @@ private File getSourceFile() {
      */
     public boolean isSourceFileAvailable() {
         if (hasPermission()) {
-            return owner == owner.getParent().getLastSuccessfulBuild() && getSourceFile().exists();
+            File sourceFile = getSourceFile();
+            return owner == owner.getParent().getLastSuccessfulBuild() && sourceFile != null && sourceFile.exists();
         }
         return false;
     }
@@ -202,7 +212,11 @@ public boolean hasPermission() {
     public String getSourceFileContent() {
         if (hasPermission()) {
             try {
-                return new TextFile(getSourceFile()).read();
+                File sourceFile = getSourceFile();
+                if (sourceFile == null) {
+                    return null;
+                }
+                return new TextFile(sourceFile).read();
             } catch (IOException e) {
                 return null;
             }
diff --git a/src/test/java/hudson/plugins/cobertura/IOUtilsTest.java b/src/test/java/hudson/plugins/cobertura/IOUtilsTest.java
new file mode 100644
index 00000000..bb56866f
--- /dev/null
+++ b/src/test/java/hudson/plugins/cobertura/IOUtilsTest.java
@@ -0,0 +1,50 @@
+package hudson.plugins.cobertura;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class IOUtilsTest {
+
+  @Test
+  public void testSanitizeRelativePathInUnix() {
+    String fileName = "../aaa/bbb";
+    String sanitizedName = IOUtils.sanitizeFilename(fileName);
+
+    assertEquals("_2e_2e_2faaa_2fbbb", sanitizedName);
+
+    fileName = "aaa/../bbb";
+    sanitizedName = IOUtils.sanitizeFilename(fileName);
+
+    assertEquals("aaa_2f_2e_2e_2fbbb", sanitizedName);
+  }
+
+  @Test
+  public void testSanitizeRelativePathInWindows() {
+    String fileName = "..\\aaa\\bbb";
+    String sanitizedName = IOUtils.sanitizeFilename(fileName);
+
+    assertEquals("_2e_2e_5caaa_5cbbb", sanitizedName);
+
+    fileName = "aaa\\..\\bbb";
+    sanitizedName = IOUtils.sanitizeFilename(fileName);
+    assertEquals( "aaa_5c_2e_2e_5cbbb", sanitizedName);
+  }
+
+
+  @Test
+  public void testSanitizeAbsolutePathInUnix() {
+    String fileName = "/aaa/bbb";
+    String sanitizedFileName = IOUtils.sanitizeFilename(fileName);
+
+    assertEquals("_2faaa_2fbbb", sanitizedFileName);
+  }
+
+  @Test
+  public void testSanitizeAbsolutePathInWindows() {
+    String fileName = "C:\\aaa\\bbb";
+    String sanitizedName = IOUtils.sanitizeFilename(fileName);
+
+    assertEquals("C_3a_5caaa_5cbbb", sanitizedName);
+  }
+}