oss-sec mailing list archives
Re: Singularity's Linux kernel vulnerability claim
From: gremlin () gremlin ru
Date: Thu, 3 May 2018 21:03:48 +0300
On 2018-05-03 17:12:06 +0000, Priedhorsky, Reid wrote:
Singularity is a container runtime targeting the high-performance computing market. It appears to be the sole product of Sylabs, Inc. [1] and has both 'community' (open source) and 'pro' (closed source) versions. Recently, the Singularity team announced on their blog [2], following up an earlier mailing list post [3], that they've found:an exploit vector to all container runtimes, that allows a malicious user to gain additional privileges within a container on hosts running kernels that do not support the PR_SET_NO_NEW_PRIVS feature
That's normal: the container runtimes (except OpenVZ VPSes) are designed to be just a resource-limiting solution. Even the (quite trivial) "undock" exploit (developed for Docker, works everywhere except OpenVZ) allows escaping the container and getting into the host system once you have got root access inside of the container.
No technical details are publically available:Sylabs has not provided details about this exploit because there is no workaround short of upgrading the kernel or uninstalling Singularity. So giving more information will only help malicious parties.We understand that details have been offered by Sylabs to at least one third party under NDA. This third party declined, but others may have accepted.
That's their right. However, publishing the zero-day exploit could be much more funny...
Sylabs does not plan to request a CVE (link in original):As of now, Sylabs will not request a CVE for this issue because it only affects old kernels and CVE's associated with PR_SET_NO_NEW_PRIVS have already been provided and resolved [4].My questions: 1. Does anyone know what is going on with this alleged vulnerability?
That's not actually a vulnerability, but just a misuse of kernel containerization features. Or would you put an elephant in a car instead of getting a truck?
2. Has anything been independently corroborated? 3. Would a CVE request be appropriate?
My guess: unlikely. -- Alexey V. Vissarionov aka Gremlin from Kremlin GPG: 8832FE9FA791F7968AC96E4E909DAC45EF3B1FA8
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- Singularity's Linux kernel vulnerability claim Priedhorsky, Reid (May 03)
- Re: Singularity's Linux kernel vulnerability claim gremlin (May 03)