What’s Vulnerable › Vulnerabilities

CVE-2019-20172

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2019-12-31 · updated 2026-06-17
• Weakness: CWE-119

Description

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.

Affected products

• SerenityOS: before 2019-12-30 — fixed in 2019-12-30

How to fix

Upgrade to a fixed version: SerenityOS 2019-12-30. Check the vendor advisory for mitigations.

References

• https://github.com/Fire30/CTF-WRITEUPS/tree/master/36c3_ctf/wisdom
• https://github.com/SerenityOS/serenity/commit/0fc24fe2564736689859e7edfa177a86dac36bf9
• https://github.com/Fire30/CTF-WRITEUPS/tree/master/36c3_ctf/wisdom
• https://github.com/SerenityOS/serenity/commit/0fc24fe2564736689859e7edfa177a86dac36bf9

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