Bamboo Security Advisory 2016-07-20
Bamboo - Deserialisation resulting in remote code execution caused by insufficient restriction on permitted deserialised classes.
Note: As of September 2014 we are no longer issuing binary bug patches, instead we create new maintenance releases for the major versions we are backporting.
Date of Advisory: 10 AM PDT (Pacific Time, -7 hours)
CVE ID:
- CVE-2016-5229 - Deserialisation in Bamboo.
Product: Bamboo
Affected Bamboo product versions:
- 2.3.1 <= version < 5.11.4.1
- 5.12.0 <= version < 5.12.3.1
Note: Bamboo version 5.10.0 and higher are not vulnerable if the "whitelist" option for XStream Serialisation is active. Prior to the fix versions listed below Bamboo defaulted to using a blacklist approach for XStream Serialisation. See Serialization protection methods for information on serialisation settings.
Fixed Bamboo product versions:
- for 5.11.x, Bamboo 5.11.4.1 has been released with a fix for this issue.
- for 5.12.x, Bamboo 5.12.3.1 has been released with a fix for this issue.
脆弱性の概要
This advisory discloses a critical severity security vulnerability which was introduced in version 2.3.1 of Bamboo. Versions of Bamboo starting with 2.3.1 before 5.11.4.1 (the fixed version for 5.11.x) and from 5.12.0 before 5.12.3.1 (the fixed version for 5.12.x) are affected by this vulnerability.
Atlassian Cloud instances have already been upgraded to a version of Bamboo which does not have the issue described on this page.
Customers who have upgraded Bamboo to version 5.11.4.1 or version 5.12.3.1 are not affected.
Customers who have downloaded and installed Bamboo >= 2.3.1 less than 5.11.4.1 (the fixed version for 5.11.x)
Customers who have downloaded and installed Bamboo >= 5.12.0 less than 5.12.3.1 (the fixed version for 5.12.x)
Please upgrade your Bamboo installations immediately to fix this vulnerability.
謝辞
We would like to credit Moritz Bechler of AgNO3 for reporting this issue to us.
Deserialisation resulting in remote code execution caused by insufficient restriction on permitted deserialised classes (CVE-2016-5229)
深刻度
Atlassian rates the severity level of this vulnerability as critical, according to the scale published in our Atlassian severity levels. The scale allows us to rank the severity as critical, high, moderate or low.
This is an independent assessment and you should evaluate its applicability to your own IT environment.
説明
Bamboo had a resource that deserialised input from build agents and did not sufficiently restrict which classes could be deserialised. To exploit this issue, attackers need to have a valid Bamboo agent fingerprint or be able to run code on a Bamboo agent.
All versions of Bamboo from 2.3.1 before 5.11.4.1 (the fixed version for 5.11.x) and from 5.12.0 before 5.12.3.1 (the fixed version for 5.12.x) are affected by this vulnerability. This issue can be tracked here: BAM-17736 - Getting issue details... STATUS
問題の軽減策
This issue can be mitigated in Bamboo version 5.10.0 and higher by setting the XStream Serialisation setting to "whitelist" which prior to the fix versions detailed in this advisory was not the default. See Serialization protection methods for information on serialisation settings.
修正
We have taken the follow steps to address this issue:
- Released Bamboo version 5.12.3.1 that contains fixes for this issue.
- Released Bamboo version 5.11.4.1 that contains fixes for this issue.
必要なアクション
Upgrade (recommended)
The vulnerabilities and fix versions are described in the description section above. Atlassian recommends that you upgrade to the latest version. This upgrade will automatically reconfigure your Bamboo to use a secure deserialisation mode.
Upgrade Bamboo to version 5.12.3.1 or higher.
If you are running Bamboo 5.11.x and cannot upgrade to bamboo 5.12.3.1 then upgrade to version 5.11.4.1.
If you are running Bamboo 5.10.x and cannot upgrade to 5.11.4.1 or 5.12.3.1 then you can follow following steps to mitigate the issue:
- Log in to Bamboo as an administrator and go to Bamboo administration > Security > Security settings which is found at /admin/configureSecurity.action for your Bamboo instance, for example http://bamboo-host/bamboo/admin/configureSecurity.action
- Under the Serialization protection methods section, set the XStream setting to Whitelist.
- 保存をクリックします。
- Check that XStream is set to Whitelist after reloading the Security Settings page.
See Serialization protection methods for information on serialisation settings.
For a full description of the latest version of Bamboo, see the release notes. You can download the latest version of Bamboo from the download centre.
サポート
この勧告に関してご質問や懸念がある場合は、https://support.atlassian.com/ja/ でサポート リクエストを作成してください。
参考
| セキュリティ バグの修正ポリシー | Atlassian の新しいポリシーにあるように、重大なセキュリティ バグの修正は、Jira と Confluence のメジャー ソフトウェア バージョンで最大 12 か月さかのぼってバックポートされます。新しいポリシーに挙げるバージョンについては、バイナリ パッチではなく新しいメンテナンス リリースを提供します。 Binary patches will no longer be released. |
| セキュリティの問題の重大度レベル | アトラシアンのセキュリティ勧告には重大度レベルと CVE ID が含まれます。重大度レベルは、それぞれの脆弱性についてアトラシアンが独自に計算した CVSS スコアに基づきます。CVSS は業界標準の脆弱性メトリックです。CVSS の詳細を FIRST.org でご確認ください。 |
| サポート終了ポリシー | サポート終了ポリシーは、製品によって異なります。詳細は、アトラシアンの「製品終了ポリシー」を参照してください。 |