CWE 311

Missing SecurityDatabase\Encrypt\Encryption of Sensitive Data

Weakness ID: 311 (Weakness Base)

Status: Draft

Description

Description Summary

The software does not encrypt sensitive or critical information before storage or transmission.

Extended Description

The lack of proper data encryption passes up the guarantees of confidentiality, integrity, and accountability that properly implemented encryption conveys.

Time of Introduction

Architecture and Design
Operation

Applicable Platforms

Languages

Language-independent

Common Consequences

Scope	Effect
Confidentiality	If the application does not use a secure channel, such as SSL, to exchange sensitive information, it is possible for an attacker with access to the network traffic to sniff packets from the connection and uncover the data. This attack is not technically difficult, but does require physical access to some portion of the network over which the sensitive data travels. This access is usually somewhere near where the user is connected to the network (such as a colleague on the company network) but can be anywhere along the path from the user to the end server.
Confidentiality Integrity	Omitting the use of encryption in any program which transfers data over a network of any kind should be considered on par with delivering the data sent to each user on the local networks of both the sender and receiver. Worse, this omission allows for the injection of data into a stream of communication between two parties -- with no means for the victims to separate valid data from invalid. In this day of widespread network attacks and password collection sniffers, it is an unnecessary risk to omit encryption from the design of any system which might benefit from it.

Scope

Effect

Confidentiality

If the application does not use a secure channel, such as SSL, to exchange sensitive information, it is possible for an attacker with access to the network traffic to sniff packets from the connection and uncover the data. This attack is not technically difficult, but does require physical access to some portion of the network over which the sensitive data travels. This access is usually somewhere near where the user is connected to the network (such as a colleague on the company network) but can be anywhere along the path from the user to the end server.

Confidentiality

Integrity

Omitting the use of encryption in any program which transfers data over a network of any kind should be considered on par with delivering the data sent to each user on the local networks of both the sender and receiver. Worse, this omission allows for the injection of data into a stream of communication between two parties -- with no means for the victims to separate valid data from invalid. In this day of widespread network attacks and password collection sniffers, it is an unnecessary risk to omit encryption from the design of any system which might benefit from it.

Likelihood of Exploit

High to Very High

Detection Methods

Manual Analysis

The characterizaton of sensitive data often requires domain-specific understanding, so manual methods are useful. However, manual efforts might not achieve desired code coverage within limited time constraints. Black box methods may produce artifacts (e.g. stored data or unencrypted network transfer) that require manual evaluation.

Effectiveness: High

Automated Analysis

Automated measurement of the entropy of an input/output source may indicate the use or lack of encryption, but human analysis is still required to distinguish intentionally-unencrypted data (e.g. metadata) from sensitive data.

Demonstrative Examples

Example 1

The following code attempts to establish a connection, read in a password, then store it to a buffer.

(Bad Code)

Example Language: C

server.sin_family = AF_INET; hp = gethostbyname(argv[1]);

if (hp==NULL) error("Unknown host");

memcpy( (char *)&server.sin_addr,(char *)hp->h_addr,hp->h_length);

if (argc < 3) port = 80;

else port = (unsigned short)atoi(argv[3]);

server.sin_port = htons(port);

if (connect(sock, (struct sockaddr *)&server, sizeof server) < 0) error("Connecting");

...

while ((n=read(sock,buffer,BUFSIZE-1))!=-1) {

write(dfd,password_buffer,n);

...

While successful, the program fails to encrypt the data before writing it to a buffer, possibly exposing it to unauthorized actors.

Example 2

The following code attempts to establish a connection to a site to communicate sensitive information.

(Bad Code)

Example Language: Java

try {

URL u = new URL("http://www.secret.example.org/");

HttpURLConnection hu = (HttpURLConnection) u.openConnection();

hu.setRequestMethod("PUT");

hu.connect();

OutputStream os = hu.getOutputStream();

hu.disconnect();

}

catch (IOException e) {

//...

}

Though a connection is successfully made, the connection is unencrypted and it is possible that all sensitive data sent to or received from the server will be read by unintended actors.

Observed Examples

Reference	Description
CVE-2009-2272	password and username stored in cleartext in a cookie
CVE-2009-1466	password stored in cleartext in a file with insecure permissions
CVE-2009-0152	chat program disables SSL in some circumstances even when the user says to use SSL.
CVE-2009-1603	Chain: product uses an incorrect public exponent when generating an RSA key, which effectively disables the encryption
CVE-2009-0964	storage of unencrypted passwords in a database
CVE-2008-6157	storage of unencrypted passwords in a database
CVE-2008-6828	product stores a password in cleartext in memory
CVE-2008-1567	storage of a secret key in cleartext in a temporary file
CVE-2008-0174	SCADA product uses HTTP Basic Authentication, which is not encrypted
CVE-2007-5778	login credentials stored unencrypted in a registry key
CVE-2002-1949	Passwords transmitted in cleartext.
CVE-2008-4122	Chain: failure to set "secure" flag in HTTPS cookie causes it to be transmitted across unencrypted HTTP.
CVE-2008-3289	Product sends password hash in cleartext in violation of intended policy.
CVE-2008-4390	Remote management feature sends sensitive information including passwords in cleartext.
CVE-2007-5626	Backup routine sends password in cleartext in email.
CVE-2004-1852	Product transmits Blowfish encryption key in cleartext.
CVE-2008-0374	Printer sends configuration information, including administrative password, in cleartext.
CVE-2007-4961	Chain: cleartext transmission of the MD5 hash of password enables attacks against a server that is susceptible to replay (CWE-294).
CVE-2007-4786	Product sends passwords in cleartext to a log server.
CVE-2005-3140	Product sends file with cleartext passwords in e-mail message intended for diagnostic purposes.

Potential Mitigations

Phase: Requirements

Clearly specify which data or resources are valuable enough that they should be protected by encryption. Require that any transmission or storage of this data/resource should use well-vetted encryption algorithms.