CVE-2019-20172 — Kernel/VM/MemoryManager

Kernel/VM/MemoryManager.cpp in SerenityOS before 2019-12-30 does not reject syscalls with pointers into the kernel-only virtual address space, which allows local users to gain privileges by overwriting a return address that was found on the kernel stack.

01What is this vulnerability?

Kernel/VM/MemoryManager.cpp in SerenityOS before 2019-12-30 does not reject syscalls with pointers into the kernel-only virtual address space, which allows local users to gain privileges by overwriting a return address that was found on the kernel stack.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-12-31T02:50:35.000Z
• Last modified: 2024-08-05T02:39:09.881Z

09References

• github.com — https://github.com/SerenityOS/serenity/commit/0fc24fe2564736689859e7edfa177a86da…
• github.com — https://github.com/Fire30/CTF-WRITEUPS/tree/master/36c3_ctf/wisdom