CVE-2019-1559 - Exposure of Sensitive Information to an Unauthorized Actor

Severity

43%

Complexity

86%

Confidentiality

48%

If an application encounters a fatal protocol error and then calls SSL_shutdown() twice (once to send a close_notify, and once to receive one) then OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid padding compared to if a 0 byte record is received with an invalid MAC. If the application then behaves differently based on that in a way that is detectable to the remote peer, then this amounts to a padding oracle that could be used to decrypt data. In order for this to be exploitable "non-stitched" ciphersuites must be in use. Stitched ciphersuites are optimised implementations of certain commonly used ciphersuites. Also the application must call SSL_shutdown() twice even if a protocol error has occurred (applications should not do this but some do anyway). Fixed in OpenSSL 1.0.2r (Affected 1.0.2-1.0.2q).

If an application encounters a fatal protocol error and then calls SSL_shutdown() twice (once to send a close_notify, and once to receive one) then OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid padding compared to if a 0 byte record is received with an invalid MAC. If the application then behaves differently based on that in a way that is detectable to the remote peer, then this amounts to a padding oracle that could be used to decrypt data. In order for this to be exploitable "non-stitched" ciphersuites must be in use. Stitched ciphersuites are optimised implementations of certain commonly used ciphersuites. Also the application must call SSL_shutdown() twice even if a protocol error has occurred (applications should not do this but some do anyway). Fixed in OpenSSL 1.0.2r (Affected 1.0.2-1.0.2q).

CVSS 3.0 Base Score 5.9. CVSS Attack Vector: network. CVSS Attack Complexity: high. CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).

CVSS 2.0 Base Score 4.3. CVSS Attack Vector: network. CVSS Attack Complexity: medium. CVSS Vector: (AV:N/AC:M/Au:N/C:P/I:N/A:N).

Demo Examples

Exposure of Sensitive Information to an Unauthorized Actor

CWE-200

The following code checks validity of the supplied username and password and notifies the user of a successful or failed login.


               
}
}
print "Login Successful";
print "Login Failed - incorrect password";
print "Login Failed - unknown username";

In the above code, there are different messages for when an incorrect username is supplied, versus when the username is correct but the password is wrong. This difference enables a potential attacker to understand the state of the login function, and could allow an attacker to discover a valid username by trying different values until the incorrect password message is returned. In essence, this makes it easier for an attacker to obtain half of the necessary authentication credentials.

While this type of information may be helpful to a user, it is also useful to a potential attacker. In the above example, the message for both failed cases should be the same, such as:


               
"Login Failed - incorrect username or password"

Exposure of Sensitive Information to an Unauthorized Actor

CWE-200

This code tries to open a database connection, and prints any exceptions that occur.


               
}
openDbConnection();
//print exception message that includes exception message and configuration file location
echo 'Check credentials in config file at: ', $Mysql_config_location, '\n';

If an exception occurs, the printed message exposes the location of the configuration file the script is using. An attacker can use this information to target the configuration file (perhaps exploiting a Path Traversal weakness). If the file can be read, the attacker could gain credentials for accessing the database. The attacker may also be able to replace the file with a malicious one, causing the application to use an arbitrary database.

Exposure of Sensitive Information to an Unauthorized Actor

CWE-200

In the example below, the method getUserBankAccount retrieves a bank account object from a database using the supplied username and account number to query the database. If an SQLException is raised when querying the database, an error message is created and output to a log file.


               
}
return userAccount;
}
userAccount = (BankAccount)queryResult.getObject(accountNumber);
Logger.getLogger(BankManager.class.getName()).log(Level.SEVERE, logMessage, ex);

The error message that is created includes information about the database query that may contain sensitive information about the database or query logic. In this case, the error message will expose the table name and column names used in the database. This data could be used to simplify other attacks, such as SQL injection (CWE-89) to directly access the database.

Exposure of Sensitive Information to an Unauthorized Actor

CWE-200

This code stores location information about the current user:


               
}...
Log.e("ExampleActivity", "Caught exception: " + e + " While on User:" + User.toString());

When the application encounters an exception it will write the user object to the log. Because the user object contains location information, the user's location is also written to the log.

Exposure of Sensitive Information to an Unauthorized Actor

CWE-200

The following is an actual MySQL error statement:


               
Warning: mysql_pconnect(): Access denied for user: 'root@localhost' (Using password: N1nj4) in /usr/local/www/wi-data/includes/database.inc on line 4

The error clearly exposes the database credentials.

Exposure of Sensitive Information to an Unauthorized Actor

CWE-200

This code displays some information on a web page.


               
Social Security Number: <%= ssn %></br>Credit Card Number: <%= ccn %>

The code displays a user's credit card and social security numbers, even though they aren't absolutely necessary.

Exposure of Sensitive Information to an Unauthorized Actor

CWE-200

The following program changes its behavior based on a debug flag.


               
} %>

The code writes sensitive debug information to the client browser if the "debugEnabled" flag is set to true .

Exposure of Sensitive Information to an Unauthorized Actor

CWE-200

This code uses location to determine the user's current US State location.

First the application must declare that it requires the ACCESS_FINE_LOCATION permission in the application's manifest.xml:


               
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

During execution, a call to getLastLocation() will return a location based on the application's location permissions. In this case the application has permission for the most accurate location possible:


               
deriveStateFromCoords(userCurrLocation);

While the application needs this information, it does not need to use the ACCESS_FINE_LOCATION permission, as the ACCESS_COARSE_LOCATION permission will be sufficient to identify which US state the user is in.

Overview

First reported 5 years ago

2019-02-27 23:29:00

Last updated 5 years ago

2019-05-22 00:29:00

Affected Software

OpenSSL Project OpenSSL

Canonical Ubuntu Linux 16.04 LTS (Long-Term Support)

16.04

Canonical Ubuntu Linux 18.04 LTS Edition

18.04

Canonical Ubuntu Linux 18.10

18.10

Debian Linux 8.0 (Jessie)

8.0

Debian Linux 9.0

9.0

NetApp Element Software

NetApp OnCommand Unified Manager for vSphere

vsphere

F5 Traffix Signaling Delivery Controller (SDC) 4.4.0

4.4.0

openSUSE Leap 15.0

15.0

openSUSE Leap 42.3

42.3

References

openSUSE-SU-2019:1076

Mailing List, Third Party Advisory

openSUSE-SU-2019:1105

Mailing List, Third Party Advisory

openSUSE-SU-2019:1173

Mailing List, Third Party Advisory

openSUSE-SU-2019:1175

Mailing List, Third Party Advisory

openSUSE-SU-2019:1432

openSUSE-SU-2019:1637

107174

Third Party Advisory, VDB Entry

RHSA-2019:2304

RHSA-2019:2437

RHSA-2019:2439

RHSA-2019:2471

RHSA-2019:3929

RHSA-2019:3931

https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=e9bbefbf0f24c57645e7ad6a5a71ae649d18ac8e

Patch, Third Party Advisory

https://kc.mcafee.com/corporate/index?page=content&id=SB10282

[debian-lts-announce] 20190301 [SECURITY] [DLA 1701-1] openssl security update

Mailing List, Third Party Advisory

FEDORA-2019-db06efdea1

FEDORA-2019-9a0a7c0986

FEDORA-2019-00c25b9379

GLSA-201903-10

Third Party Advisory

https://security.netapp.com/advisory/ntap-20190301-0001/

Patch, Third Party Advisory

https://security.netapp.com/advisory/ntap-20190301-0002/

Third Party Advisory

https://security.netapp.com/advisory/ntap-20190423-0002/

Third Party Advisory

https://support.f5.com/csp/article/K18549143

Third Party Advisory

https://support.f5.com/csp/article/K18549143?utm_source=f5support&amp;utm_medium=RSS

USN-3899-1

Third Party Advisory

DSA-4400

Third Party Advisory

https://www.openssl.org/news/secadv/20190226.txt

Vendor Advisory

https://www.oracle.com/security-alerts/cpujan2020.html

https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html

Third Party Advisory

https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html

https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html

https://www.tenable.com/security/tns-2019-02

Patch, Third Party Advisory

https://www.tenable.com/security/tns-2019-03

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