CVE-2014-0017: Low severity libssh libssh vulnerability
A flaw was found in libssh server. When accepting a new connection, the server forks and the child process handles the request. The RANDbytes() function of openssl doesn't reset its state after the fork, but simply adds the current process id (getpid) to the PRNG state, which is not guaranteed to be unique. The most important consequence is that servers using EC (ECDSA) or DSA certificates may under certain conditions leak their private key.
Other sources
The RANDbytes function in libssh before 0.6.3, when forking is enabled, does not properly reset the state of the OpenSSL pseudo-random number generator (PRNG), which causes the state to be shared between children processes and allows local users to obtain sensitive information by leveraging a pid collision.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
libssh serverto a version that resolves this vulnerability.Fixed in 0.6.3 - Compensating control
As an immediate mitigation for servers using libssh with forking enabled (fork-on-new-connection), avoid exposing the service to untrusted local users until the libssh upgrade to 0.6.3 is applied, since pid collisions in the shared OpenSSL PRNG state can allow local users to obtain sensitive information and may under certain conditions leak private keys for EC (ECDSA) or DSA certificates.
Event History
Frequently Asked Questions
What is the severity of CVE-2014-0017?
CVE-2014-0017 has a medium severity, potentially impacting the security of systems using affected versions of libssh.
How do I fix CVE-2014-0017?
To fix CVE-2014-0017, update libssh to version 0.6.3 or later, as this version addresses the vulnerability.
Which versions of libssh are affected by CVE-2014-0017?
CVE-2014-0017 affects libssh versions up to and including 0.6.2, as well as specific earlier versions.
What was the issue in CVE-2014-0017?
CVE-2014-0017 involves the RAND_bytes() function not resetting its state after a fork, leading to potential security exposure.
Is CVE-2014-0017 exploited in the wild?
As of the latest information, there are no confirmed reports of CVE-2014-0017 being exploited in the wild.