CVE-2022-31116 Incorrect handling of invalid surrogate pair characters in ujson
Attackers can corrupt strings and overwrite dictionary values by sending JSON with invalid surrogate pairs to applications using UltraJSON.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-31116?
CVE-2022-31116 is a high-severity vulnerability in Fedoraproject Fedora, published on 5 Jul 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Affected versions were found to improperly decode certain characters. JSON strings that contain escaped surrogate characters not part of a proper surrogate pair were decoded incorrectly. Besides corrupting strings, this allowed for potential key confusion and value overwriting in dictionaries. All users parsing JSON from untrusted sources are vulnerable. From version 5.4.0, UltraJSON decodes lone surrogates in the same way as the standard library's `json` module does, preserving them in the parsed output. Users are advised to upgrade. There are no known workarounds for this issue.
Weakness: CWE-670
Which versions are affected by CVE-2022-31116?
3 open source packages ship an affected version, including ujson. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
ujson PyPI | All versions | 5.4.0 |
ujson PyPI | All versions | 5.4.0 |
ujson PyPI | All versions | 5.4.0 |
Products include Fedoraproject Fedora, Ultrajson Project Ultrajson.
How do I fix CVE-2022-31116?
Upgrade ujson to 5.4.0 or later.
Is CVE-2022-31116 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-31116 exists.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as DEBIAN-CVE-2022-31116, GHSA-wpqr-jcpx-745r, PYSEC-2026-1057, UBUNTU-CVE-2022-31116.