CVE-2021-39212 (published 2021-09-13T18:15Z)

ImageMagick is free software delivered as a ready-to-run binary distribution or as source code that you may use, copy, modify, and distribute in both open and proprietary applications. In affected versions and in certain cases, Postscript files could be read and written when specifically excluded by a `module` policy in `policy.xml`. ex. <policy domain="module" rights="none" pattern="PS" />. The issue has been resolved in ImageMagick 7.1.0-7 and in 6.9.12-22. Fortunately, in the wild, few users utilize the `module` policy and instead use the `coder` policy that is also our workaround recommendation: <policy domain="coder" rights="none" pattern="{PS,EPI,EPS,EPSF,EPSI}" />.

Severity: LOW
CVSS v2 base score: 3.6 (AV:L/AC:L/Au:N/C:P/I:P/A:N)
CVSS v3 base score: 3.6, LOW (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N)

Weakness information:
cwe_id: CWE-668
cwe_name: Exposure of Resource to Wrong Sphere
description: The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.
extended_description: 
            Resources such as files and directories may be inadvertently exposed through mechanisms such as insecure permissions, or when a program accidentally operates on the wrong object. For example, a program may intend that private files can only be provided to a specific user. This effectively defines a control sphere that is intended to prevent attackers from accessing these private files. If the file permissions are insecure, then parties other than the user will be able to access those files.
            A separate control sphere might effectively require that the user can only access the private files, but not any other files on the system. If the program does not ensure that the user is only requesting private files, then the user might be able to access other files on the system.
            In either case, the end result is that a resource has been exposed to the wrong party.
         
         

Fix information:
repo_url: https://github.com/ImageMagick/ImageMagick
commit_details: repo_url: https://github.com/ImageMagick/ImageMagick
author: Dirk Lemstra
author_date: 2021-09-11 17:00:50+02:00
msg: Use the correct rights.
repository: repo_url: https://github.com/ImageMagick/ImageMagick
repo_name: ImageMagick/ImageMagick
description: 🧙‍♂️ ImageMagick 7
repo_language: C
owner: ImageMagick
file_changes: filename: module.c
change_type: ModificationType.MODIFY
diff: @@ -1255,7 +1255,7 @@ MagickPrivate MagickBooleanType OpenModule(const char *module,
   p=GetCoderInfo(module,exception);
   if (p != (CoderInfo *) NULL)
     (void) CopyMagickString(module_name,p->name,MagickPathExtent);
-  rights=AllPolicyRights;
+  rights=ReadPolicyRights|WritePolicyRights;
   if (IsRightsAuthorized(ModulePolicyDomain,rights,module_name) == MagickFalse)
     {
       errno=EPERM;

programming_language: Objective-C
filename: static.c
change_type: ModificationType.MODIFY
diff: @@ -240,7 +240,7 @@ MagickExport MagickBooleanType RegisterStaticModule(const char *module,
   p=GetCoderInfo(module,exception);
   if (p != (CoderInfo *) NULL)
     (void) CopyMagickString(module_name,p->name,MagickPathExtent);
-  rights=AllPolicyRights;
+  rights=ReadPolicyRights|WritePolicyRights;
   if (IsRightsAuthorized(ModulePolicyDomain,rights,module_name) == MagickFalse)
     {
       errno=EPERM;
@@ -283,18 +283,22 @@ MagickExport MagickBooleanType RegisterStaticModule(const char *module,
 */
 MagickExport void RegisterStaticModules(void)
 {
+  PolicyRights
+    rights;
+
   size_t
     extent;
 
   ssize_t
     i;
 
+  rights=ReadPolicyRights|WritePolicyRights;
   extent=sizeof(MagickModules)/sizeof(MagickModules[0]);
   for (i=0; i < (ssize_t) extent; i++)
   {
     if (MagickModules[i].registered == MagickFalse)
       {
-        if (IsRightsAuthorized(ModulePolicyDomain,AllPolicyRights,
+        if (IsRightsAuthorized(ModulePolicyDomain,rights,
               MagickModules[i].module) == MagickFalse)
           continue;
         (void) (MagickModules[i].register_module)();

programming_language: Objective-C
repo_url: https://github.com/ImageMagick/ImageMagick
commit_details: repo_url: https://github.com/ImageMagick/ImageMagick
author: Dirk Lemstra
author_date: 2021-09-11 12:30:42+02:00
msg: Added missing policy checks in RegisterStaticModules.
repository: repo_url: https://github.com/ImageMagick/ImageMagick
repo_name: ImageMagick/ImageMagick
description: 🧙‍♂️ ImageMagick 7
repo_language: C
owner: ImageMagick
file_changes: filename: static.c
change_type: ModificationType.MODIFY
diff: @@ -240,7 +240,7 @@ MagickExport MagickBooleanType RegisterStaticModule(const char *module,
   p=GetCoderInfo(module,exception);
   if (p != (CoderInfo *) NULL)
     (void) CopyMagickString(module_name,p->name,MagickPathExtent);
-  rights=ReadPolicyRights;
+  rights=AllPolicyRights;
   if (IsRightsAuthorized(ModulePolicyDomain,rights,module_name) == MagickFalse)
     {
       errno=EPERM;
@@ -294,6 +294,9 @@ MagickExport void RegisterStaticModules(void)
   {
     if (MagickModules[i].registered == MagickFalse)
       {
+        if (IsRightsAuthorized(ModulePolicyDomain,AllPolicyRights,
+              MagickModules[i].module) == MagickFalse)
+          continue;
         (void) (MagickModules[i].register_module)();
         MagickModules[i].registered=MagickTrue;
       }

programming_language: Objective-C