FreeBSD : Multiple vulnerabilities in Botan (4cd9b19f-f66d-11e5-b94c-001999f8d30b)

This script is Copyright (C) 2016 Tenable Network Security, Inc.


Synopsis :

The remote FreeBSD host is missing a security-related update.

Description :

The botan developers reports :

Infinite loop in modular square root algorithm - The ressol function
implements the Tonelli-Shanks algorithm for finding square roots could
be sent into a nearly infinite loop due to a misplaced conditional
check. This could occur if a composite modulus is provided, as this
algorithm is only defined for primes. This function is exposed to
attacker controlled input via the OS2ECP function during ECC point
decompression.

Heap overflow on invalid ECC point - The PointGFp constructor did not
check that the affine coordinate arguments were less than the prime,
but then in curve multiplication assumed that both arguments if
multiplied would fit into an integer twice the size of the prime.

The bigint_mul and bigint_sqr functions received the size of the
output buffer, but only used it to dispatch to a faster algorithm in
cases where there was sufficient output space to call an unrolled
multiplication function.

The result is a heap overflow accessible via ECC point decoding, which
accepted untrusted inputs. This is likely exploitable for remote code
execution.

On systems which use the mlock pool allocator, it would allow an
attacker to overwrite memory held in secure_vector objects. After this
point the write will hit the guard page at the end of the mmapped
region so it probably could not be used for code execution directly,
but would allow overwriting adjacent key material.

See also :

http://botan.randombit.net/security.html
http://www.nessus.org/u?f25a52a2

Solution :

Update the affected package.

Risk factor :

Critical / CVSS Base Score : 10.0
(CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C)

Family: FreeBSD Local Security Checks

Nessus Plugin ID: 90287 ()

Bugtraq ID:

CVE ID: CVE-2016-2194
CVE-2016-2195

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