Denial of service in linux-nfs.org products - CVE-2017-8779
Published: May 4, 2017 / Updated: September 14, 2018
Vulnerability identifier: #VU6435
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:A/U:Green
CVE-ID: CVE-2017-8779
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vendor: ntirpc
linux-nfs.org
linux-nfs.org
Affected software:
ntirpc
libtirpc
RPCBind
ntirpc
libtirpc
RPCBind
Detailed vulnerability description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to an error in xdr_bytes() and xdr_string() functions when processing RPC data during memory allocation within rpcbind implementation. A remote unauthenticated attacker can send a specially crafted UDP request to port 111 and consume up to 4 gigabytes of memory per request.
Successful exploitation of this vulnerability may result in denial of service (DoS) conditions.
How to mitigate CVE-2017-8779
The vulnerability affects rpcbind through 0.2.4, LIBTIRPC through 1.0.1 and 1.0.2-rc through 1.0.2-rc3, and NTIRPC through 1.4.3.
To mitigate the issue install the appropriate patch from your OS vendor's website.
As a temporary solution, block all UDP traffic to port 111.
To mitigate the issue install the appropriate patch from your OS vendor's website.
As a temporary solution, block all UDP traffic to port 111.