Bug 1194213

Summary: xrdp: denial of service when validating user accounts against plain passwd files/via shadow-utils
Product: [Other] Security Response Reporter: Vasyl Kaigorodov <vkaigoro>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED RAWHIDE QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: bazanluis20, itamar, jrusnack
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2015-07-15 18:42:18 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1194214, 1194215    
Bug Blocks:    

Description Vasyl Kaigorodov 2015-02-19 10:54:16 UTC 
It was discovered by Ken Milnore that xrdp 0.6.1 and earlier, when
validating user accounts against plain passwd files or via
shadow-utils, does not check for NULL returns from crypt(). [1]

--- sesman/verify_user.c ---
  encr = crypt(pass,salt);
  if (g_strncmp(encr, hash, 34) != 0)
  {
    return 0;
  }
  return 1;
----------------------------

A NULL return crashes the xrdp-sesman daemon resulting in an xrdp
server denial of service (for all modules that use xrdp's session
manager for user authentication via old-style passwd files or via
shadow passwords).

This has been fixed by upstream in its development branch. [2]

[1] http://sourceforge.net/p/xrdp/mailman/message/32985523/
[2] https://github.com/neutrinolabs/xrdp/commit/851c762ee722
Comment 1 Vasyl Kaigorodov 2015-02-19 10:54:39 UTC 
Created xrdp tracking bugs for this issue:

Affects: fedora-all [bug 1194214]
Affects: epel-all [bug 1194215]
Comment 2 Itamar Reis Peixoto 2015-07-15 18:42:18 UTC 
fixed in rawhide
Comment 3 Fedora Update System 2015-07-30 00:45:52 UTC 
xrdp-0.6.1-11.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.