A vulnerability was found in Microsoft Access 2010 (Database Software). It has been declared as problematic. This vulnerability affects an unknown function of the component VBA. The manipulation with the input value NULL leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability.

The bug was discovered 07/04/2014. The weakness was released 04/21/2015 by Marc Ruef with scip AG as sID 66976 as confirmed entry (scip VulDB). The advisory is shared for download at scip.ch. The public release happened without coordination with the vendor. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details and also a public exploit are known. The MITRE ATT&CK project declares the attack technique as T1499. Assigning the datatype NULL to a string variable may cause the application to crash.

A public exploit has been developed by Marc Ruef in VBA and been published immediately after the advisory. It is possible to download the exploit at scip.ch. It is declared as proof-of-concept. The code used by the exploit is:

Public Sub NullExploit()
    Dim cn As New ADODB.Connection
    Dim rs As New ADODB.Recordset
    Dim sResult As String
    
    cn.Open "vuldb"
    rs.Open "SELECT * FROM tbl_vulnerabilities WHERE id='66976'", cn
    
    With rs
        If Not .EOF And Not .BOF Then
            sResult = .Fields("source_cve") 'will cause DoS
        End If
    End With

    MsgBox sResult

    rs.Close
    Set rs = Nothing
    cn.Close
    Set cn = Nothing
End Sub

The best possible mitigation is suggested to be Workaround. A possible mitigation has been published immediately after the disclosure of the vulnerability. The vulnerability will be addressed with the following lines of code:

sResult = CVar(.Fields("source_cve"))

Productinfo

Type

• Database Software

Vendor

• Microsoft

Name

• Access

Version

• 2010

License

• commercial

CPE 2.3info

• 🔍

CPE 2.2info

• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

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