A vulnerability patched by the Internet Systems Consortium (ISC) in the BIND DNS software several years ago has been found to affect Linux distributions that use packages derived from BIND releases prior to the security hole being fixed.
The high severity vulnerability, tracked as CVE-2016-2848, was discovered by Toshifumi Sakaguch and disclosed by ISC last week. The issue can be exploited remotely to cause a denial-of-service (DoS) condition on both authoritative and recursive servers by sending them malformed DNS packets.
The vulnerability was patched in ISC-distributed versions with the change tracked as #3548, first included in BIND 9 releases in May 2013. The problem is that some software vendors, including several OS distributions, have been using repackaged versions forked from ISC’s source code before the fix was implemented.
ISC has not found any evidence that the flaw has been exploited in the wild, but the organization’s security officer, Michael McNally, warned that a proof-of-concept (PoC) exists in a public bug repository.
“Since information concerning the vulnerability, including a reproduction script, exists in a public bug repository we urge you to update vulnerable binary packages as soon as possible,” McNally advised.
Red Hat said the vulnerability does not affect Red Hat Enterprise Linux 7. The company has released updates for RHEL 5 and 6, but it will not address the flaw in version 4. Updates that patch the issue have also been released for Debian, SUSE Linux Enterprise and Ubuntu.
“The CHANGES file distributed with every version of BIND source contains a chronological list of source code changes in each branch’s history. Safe versions of BIND contain fix #3548,” ISC said in its advisory. “If you did not receive source code with your distribution of BIND and cannot check CHANGES, check with the package provider who has furnished the BIND distribution you are using. Current versions of BIND available from ISC are confirmed to be free of the vulnerability.”
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