-[ANNOUNCE] Hadoop-1.0.4 release, with Security fix
Matt Foley 2012-10-12, 21:01
The release of Hadoop-1.0.4 has been voted, accepted, and posted.
It is available in SVN and Maven, as well as at
It is still propagating to mirrors, and should be available on all mirrors
by this time Saturday.
The documentation update is still being worked on and will be available by
This release is noteworthy for including a Security bug fix, related to
discovered by Daryn Sharp and fixed by Owen O'Malley. The CVE announcement
*CVE-2012-4449: Apache Hadoop security token vulnerabilities
Vendor: The Apache Software Foundation
0.20.X: All versions
0.23: All versions before 0.23.4
1.0: All versions before 1.0.4
2.0: All versions before 2.0.2
Users who have enabled Hadoop's Kerberos security features.
Malicious users may crack the secret keys used to sign security
tokens, thus granting them the ability to fabricate tokens for
privilege escalation. Malicious users may also launch unauthorized
tasks as an arbitrary user for privilege escalation.
When Hadoop's security features are enabled, clients initially present
Kerberos credentials to authenticate to a service such as the
NameNode. A client may then request a security token for subsequent
authentication within the Hadoop cluster. The client receives a
security token and a corresponding signature for the token, generated
using the HMAC algorithm and a SHA1 hash.
Token passwords are generated using a trivial secret key length (20
bits). A key of this size can be brute forced in at most a few
seconds. Once the secret is cracked, one can generate arbitrary
tokens to impersonate other users. These fraudulent tokens may be
used to gain unauthorized access to data or disrupt services within
the cluster. With default secret key rolling values, a cracked secret
may often be exploited for a couple days before another secret has to
Some token-based services, such as the NameNode's delegation tokens
for the namespace, are immune from a compromised secret key because
they record the generated tokens. A fraudulent token with a valid
password will rejected since the service will know it did not generate
the token. Services that generate a token on behalf of another
service and rely on a shared secret for the other service to validate
the token's password are especially vulnerable.
HDFS (all versions):
Malicious clients cannot gain unauthorized access to the namespace.
Malicious clients may however gain full access (read, write, and
delete) to any block based on knowledge of the block id.
Malicious clients may intercept task data, task logs, alter task
status, and disrupt tasks from executing or completing. A malicious
client may also inject data into a Pipes-based job.
Yarn (2.x only):
Malicious clients may perform the same attacks as MapReduce. An
unauthorized yarn task may be launched unbeknownst to the
ResourceManager. Additionally, the security tokens for launching
tasks do not contain the job submitter. The user for task execution
is specified in an untrusted container launch context, thus allowing a
task to be launched as an arbitrary user. When combined, an
unauthorized task may be launched as an arbitrary user.
Other Hadoop projects:
Hadoop projects using the token management framework may be
susceptible if their services do not store the tokens issued, or if a
service generates tokens for other services. This includes Apache
HBase version 0.92.0 or higher when the Kerberos-based security
features are enabled.
Users should immediately upgrade to the latest applicable release
(0.23.4, 1.0.4 or later, or 2.0.2), or should immediately apply the
patch provided below to their systems.
Credit: This issue was discovered by Daryn Sharp of Yahoo! Inc.