CVE-2018-20997 Use after free in openssl
A use-after-free vulnerability in the Rust openssl crate allows attackers to potentially execute arbitrary code or cause a denial of service during CMS signing operations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2018-20997?
CVE-2018-20997 is a critical use after free vulnerability in n/a, published on 26 Aug 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An issue was discovered in the openssl crate before 0.10.9 for Rust. A use-after-free occurs in CMS Signing.
Weakness: CWE-416
Which versions are affected by CVE-2018-20997?
3 open source packages ship an affected version, including openssl. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
openssl crates.io | From 0.10.8 | 0.10.9 |
openssl crates.io | From 0.10.8 | 0.10.9 |
openssl crates.io | From 0.10.8 | 0.10.9 |
Products include Rust-Openssl Project Rust-Openssl.
How do I fix CVE-2018-20997?
Upgrade openssl to 0.10.9 or later.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2018-20997 being exploited?
There is no known exploitation of CVE-2018-20997 in the wild and no public exploit code.
Other vulnerabilities in n/a
- CVE-2026-41898 rust-openssl: Unchecked callback length in PSK/cookie trampolines leaks adjacent memory to peer
- CVE-2026-41681 rust-openssl: MdCtxRef::digest_final() writes past caller buffer with no length check
- CVE-2016-10931 Improper Certificate Validation in openssl
- CVE-2026-41676 rust-openssl: Deriver::derive and PkeyCtxRef::derive can overflow short buffers on OpenSSL 1.1.1
- CVE-2026-41678 rust-openssl: Incorrect bounds assertion in aes key wrap
Sources
Also known as GHSA-xjxc-vfw2-cg96, RUSTSEC-2018-0010.