43%
86%
48%
PostgreSQL 8.4.x before 8.4.11, 9.0.x before 9.0.7, and 9.1.x before 9.1.3 truncates the common name to only 32 characters when verifying SSL certificates, which allows remote attackers to spoof connections when the host name is exactly 32 characters.
PostgreSQL 8.4.x before 8.4.11, 9.0.x before 9.0.7, and 9.1.x before 9.1.3 truncates the common name to only 32 characters when verifying SSL certificates, which allows remote attackers to spoof connections when the host name is exactly 32 characters.
CVSS 2.0 Base Score 4.3. CVSS Attack Vector: network. CVSS Attack Complexity: medium. CVSS Vector: (AV:N/AC:M/Au:N/C:N/I:P/A:N).
This code checks the certificate of a connected peer.
foo=SSL_get_verify_result(ssl);
// certificate looks good, host can be trustedIn this case, because the certificate is self-signed, there was no external authority that could prove the identity of the host. The program could be communicating with a different system that is spoofing the host, e.g. by poisoning the DNS cache or using a MITM attack to modify the traffic from server to client.
The following OpenSSL code obtains a certificate and verifies it.
}
// do secret thingsEven though the "verify" step returns X509_V_OK, this step does not include checking the Common Name against the name of the host. That is, there is no guarantee that the certificate is for the desired host. The SSL connection could have been established with a malicious host that provided a valid certificate.
The following OpenSSL code ensures that there is a certificate and allows the use of expired certificates.
//do stuffIf the call to SSL_get_verify_result() returns X509_V_ERR_CERT_HAS_EXPIRED, this means that the certificate has expired. As time goes on, there is an increasing chance for attackers to compromise the certificate.
The following OpenSSL code ensures that there is a certificate before continuing execution.
// got a certificate, do secret thingsBecause this code does not use SSL_get_verify_results() to check the certificate, it could accept certificates that have been revoked (X509_V_ERR_CERT_REVOKED). The software could be communicating with a malicious host.
The following OpenSSL code ensures that the host has a certificate.
}
// got certificate, host can be trusted//foo=SSL_get_verify_result(ssl);//if (X509_V_OK==foo) ...Note that the code does not call SSL_get_verify_result(ssl), which effectively disables the validation step that checks the certificate.
This example demonstrates a shopping interaction in which the user is free to specify the quantity of items to be purchased and a total is calculated.
...The user has no control over the price variable, however the code does not prevent a negative value from being specified for quantity. If an attacker were to provide a negative value, then the user would have their account credited instead of debited.
This example asks the user for a height and width of an m X n game board with a maximum dimension of 100 squares.
.../* board dimensions */die("No integer passed: Die evil hacker!\n");die("No integer passed: Die evil hacker!\n");die("Value too large: Die evil hacker!\n");While this code checks to make sure the user cannot specify large, positive integers and consume too much memory, it does not check for negative values supplied by the user. As a result, an attacker can perform a resource consumption (CWE-400) attack against this program by specifying two, large negative values that will not overflow, resulting in a very large memory allocation (CWE-789) and possibly a system crash. Alternatively, an attacker can provide very large negative values which will cause an integer overflow (CWE-190) and unexpected behavior will follow depending on how the values are treated in the remainder of the program.
The following example shows a PHP application in which the programmer attempts to display a user's birthday and homepage.
echo "Birthday: $birthday<br>Homepage: <a href=$homepage>click here</a>"The programmer intended for $birthday to be in a date format and $homepage to be a valid URL. However, since the values are derived from an HTTP request, if an attacker can trick a victim into clicking a crafted URL with <script> tags providing the values for birthday and / or homepage, then the script will run on the client's browser when the web server echoes the content. Notice that even if the programmer were to defend the $birthday variable by restricting input to integers and dashes, it would still be possible for an attacker to provide a string of the form:
2009-01-09--If this data were used in a SQL statement, it would treat the remainder of the statement as a comment. The comment could disable other security-related logic in the statement. In this case, encoding combined with input validation would be a more useful protection mechanism.
Furthermore, an XSS (CWE-79) attack or SQL injection (CWE-89) are just a few of the potential consequences when input validation is not used. Depending on the context of the code, CRLF Injection (CWE-93), Argument Injection (CWE-88), or Command Injection (CWE-77) may also be possible.
This function attempts to extract a pair of numbers from a user-supplied string.
}
die("Did not specify integer value. Die evil hacker!\n");/* proceed assuming n and m are initialized correctly */This code attempts to extract two integer values out of a formatted, user-supplied input. However, if an attacker were to provide an input of the form:
123:then only the m variable will be initialized. Subsequent use of n may result in the use of an uninitialized variable (CWE-457).
The following example takes a user-supplied value to allocate an array of objects and then operates on the array.
}list[0] = new Widget();die("Negative value supplied for list size, die evil hacker!");This example attempts to build a list from a user-specified value, and even checks to ensure a non-negative value is supplied. If, however, a 0 value is provided, the code will build an array of size 0 and then try to store a new Widget in the first location, causing an exception to be thrown.
This application has registered to handle a URL when sent an intent:
}......
}
}int length = URL.length();...The application assumes the URL will always be included in the intent. When the URL is not present, the call to getStringExtra() will return null, thus causing a null pointer exception when length() is called.
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