[security] Go 1.5.3 is released

no extension

2週間前の話ですみません。 1月14日に Go 言語コンパイラ 1.5.3 が出ています。 メインは math/big パッケージの不具合修正です。

リスクとしては大したことはないですが, Web アプリケーションまたは TLS の実装を Go 言語で行っている方は要更新です。

This issue can affect RSA computations in crypto/rsa, which is used by crypto/tls. TLS servers on 32-bit systems could plausibly leak their RSA private key due to this issue. Other protocol implementations that create many RSA signatures could also be impacted in the same way.
Specifically, incorrect results in one part of the RSA Chinese Remainder computation can cause the result to be incorrect in such a way that it leaks one of the primes. While RSA blinding should prevent an attacker from crafting specific inputs that trigger the bug, on 32-bit systems the bug can be expected to occur at random around one in 2^26 times. Thus collecting around 64 million signatures (of known data) from an affected server should be enough to extract the private key used.
On 64-bit systems, the frequency of the bug is so low (less than one in 2^50) that it would be very difficult to exploit. Nonetheless, everyone is strongly encouraged to upgrade.

CVE-2015-8618 Carry propagation in Int.Exp Montgomery code in math/big library

CVSSv2 基本評価値 2.6 (AV:N/AC:H/Au:N/C:P/I:N/A:N)Redhat による評価

基本評価基準 評価値
攻撃元区分(AV) ネットワーク(N)
攻撃条件の複雑さ(AC) 高(H)
攻撃前の認証要否(Au) 不要(N)
情報漏えいの可能性(機密性への影響, C) 部分的(P)
情報改ざんの可能性(完全性への影響, I) なし(N)
業務停止の可能性(可用性への影響, A) なし(N)