CVE-2022-42323

Xenstore: Cooperating guests can create arbitrary numbers of nodes T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Since the fix of XSA-322 any Xenstore node owned by a removed domain will be modified to be owned by Dom0. This will allow two malicious guests working together to create an arbitrary number of Xenstore nodes. This is possible by domain A letting domain B write into domain As local Xenstore tree. Domain B can then create many nodes and reboot. The nodes created by domain B will now be owned by Dom0. By repeating this process over and over again an arbitrary number of nodes can be created, as Dom0s number of nodes isnt limited by Xenstore quota.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• http://www.openwall.com/lists/oss-security/2022/11/01/9
• http://xenbits.xen.org/xsa/advisory-419.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YTMITQBGC23MSDHUCAPCVGLMVXIBXQTQ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YZVXG7OOOXCX6VIPEMLFDPIPUTFAYWPE/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZLI2NPNEH7CNJO3VZGQNOI4M4EWLNKPZ/
• https://security.gentoo.org/glsa/202402-07
• https://www.debian.org/security/2022/dsa-5272
• https://xenbits.xenproject.org/xsa/advisory-419.txt
• http://www.openwall.com/lists/oss-security/2022/11/01/9
• http://xenbits.xen.org/xsa/advisory-419.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YTMITQBGC23MSDHUCAPCVGLMVXIBXQTQ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YZVXG7OOOXCX6VIPEMLFDPIPUTFAYWPE/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZLI2NPNEH7CNJO3VZGQNOI4M4EWLNKPZ/
• https://security.gentoo.org/glsa/202402-07
• https://www.debian.org/security/2022/dsa-5272
• https://xenbits.xenproject.org/xsa/advisory-419.txt