Skype file: URI handler case-sensitive comparison security bypass

skype-fileuri-case-security-bypass (43044) The risk level is classified as MediumMedium Risk

Description:

Skype could allow a remote attacker to bypass security restrictions, caused by improper filtering of certain executable file extensions. By persuading a victim to open a specially-crafted file: URI containing certain case characters that circumvent case-sensitive comparisons, an attacker could bypass security warning dialogs and blacklist filtering to possibly execute arbitrary code on the system.

*CVSS:

Base Score: 4.3
  Access Vector: Network
  Access Complexity: Medium
  Authentication: None
  Confidentiality Impact: None
  Integrity Impact: Partial
  Availability Impact: None
 
Temporal Score: 3.2
  Exploitability: Unproven
  Remediation Level: Official-Fix
  Report Confidence: Confirmed

Consequences:

Bypass Security

Remedy:

Refer to SKYPE-SB/2008-003 for patch, upgrade or suggested workaround information. See References.

References:

  • iDefense Labs PUBLIC ADVISORY: 06.04.08: Skype File URI Security Bypass Code Execution Vulnerability.
  • SKYPE-SB/2008-003: Skype File URI Security Bypass Code Execution Vulnerability.
  • BID-29553: Skype 'file://' URI Handler Bypass Remote Code Execution Vulnerability
  • CVE-2008-2545: Skype 3.6.0.248, and other versions before 3.8.0.139, uses a case-sensitive comparison when checking for dangerous extensions, which allows user-assisted remote attackers to bypass warning dialogs and possibly execute arbitrary code via a file: URI with a dangerous extension that uses a different case.
  • SA30547: Skype File URI Code Execution Vulnerability
  • SECTRACK ID: 1020201: Skype 'file://' URL Warning Can Be Bypassed By Remote USers
  • VUPEN/ADV-2008-1749: Skype for Windows File URI Handling Code Execution Vulnerability

Platforms Affected:

  • Skype Skype 3.0.0.106 Beta
  • Skype Skype 3.0.0.123 Beta
  • Skype Skype 3.0.0.137 Beta
  • Skype Skype 3.0.0.154 Beta
  • Skype Skype 3.0.0.190
  • Skype Skype 3.0.0.198
  • Skype Skype 3.0.0.205
  • Skype Skype 3.0.0.209
  • Skype Skype 3.0.0.214
  • Skype Skype 3.0.0.216
  • Skype Skype 3.0.0.217
  • Skype Skype 3.0.0.218
  • Skype Skype 3.1.0.112 Beta
  • Skype Skype 3.1.0.134 Beta
  • Skype Skype 3.1.0.144
  • Skype Skype 3.1.0.147
  • Skype Skype 3.1.0.150
  • Skype Skype 3.1.0.152
  • Skype Skype 3.2.0.115 Beta
  • Skype Skype 3.2.0.145
  • Skype Skype 3.2.0.148
  • Skype Skype 3.2.0.152
  • Skype Skype 3.2.0.158
  • Skype Skype 3.2.0.163
  • Skype Skype 3.2.0.175
  • Skype Skype 3.2.0.53 Beta
  • Skype Skype 3.2.0.63 Beta
  • Skype Skype 3.2.0.82 Beta
  • Skype Skype 3.5.0.107 Beta
  • Skype Skype 3.5.0.158 Beta
  • Skype Skype 3.5.0.178 Beta
  • Skype Skype 3.5.0.202
  • Skype Skype 3.5.0.214
  • Skype Skype 3.5.0.229
  • Skype Skype 3.5.0.234
  • Skype Skype 3.5.0.239
  • Skype Skype 3.6.0.127 Beta
  • Skype Skype 3.6.0.159 Beta
  • Skype Skype 3.6.0.216
  • Skype Skype 3.6.0.244
  • Skype Skype 3.6.0.248
  • Skype Skype 3.8.0.115
  • Skype Skype 3.8.0.96 Beta

Reported:

Jun 04, 2008

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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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