Botan 1.11.28 and 1.10.12 were released fixing several serious security bugs including a heap overflow.
I am listed as the maintainer for this ebuild but don't use Gentoo much anymore (I still like it, but it can be time consuming to maintain...) so cannot provide an update. I don't believe there are any build related changes that affect an upgrade vs the current ebuilds.
libbotan 1.11 is masked so only tracking the security issues in 1.10-series
2016-02-01 (CVE-2016-2195): 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 mmap’ed region so it probably could not be used for code execution directly, but would allow overwriting adjacent key material.
Found by Alex Gaynor fuzzing with AFL
Introduced in 1.9.18, fixed in 1.11.27 and 1.10.11
2016-02-01 (CVE-2016-2194): Infinite loop in modulur 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. Found by AFL
Introduced in 1.7.15, fixed in 1.11.27 and 1.10.11
Arches, please stabilize:
Stable targets: amd64 hppa ppc ppc64 sparc x86
Stable for HPPA PPC64.
Maintainer(s), please cleanup.
Security, please add it to the existing request, or file a new one.
(In reply to Agostino Sarubbo from comment #8)
> Maintainer(s), please cleanup.
New GLSA created.
This issue was resolved and addressed in
GLSA 201612-38 at https://security.gentoo.org/glsa/201612-38
by GLSA coordinator Aaron Bauman (b-man).