CVE-2022-35923 Inefficient Regular Expression Complexity in v8n
An attacker can cause a denial of service in the v8n validation library by exploiting inefficient regular expressions in lowercase and uppercase checks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-35923?
CVE-2022-35923 is a high-severity denial of service vulnerability in imbrn v8n, published on 2 Aug 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
v8n is a javascript validation library. Versions of v8n prior to 1.5.1 were found to have an inefficient regular expression complexity in the `lowercase()` and `uppercase()` regex which could lead to a denial of service attack. In testing of the `lowercase()` function a payload of 'a' + 'a'.repeat(i) + 'A' with 32 leading characters took 29443 ms to execute. The same issue happens with uppercase(). Users are advised to upgrade. There are no known workarounds for this issue.
Which versions are affected by CVE-2022-35923?
2 open source packages ship an affected version, including v8n. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
v8n npm | All versions | 1.5.1 |
v8n npm | All versions | 1.5.1 |
Products include V8n Project V8n.
How do I fix CVE-2022-35923?
Upgrade v8n to 1.5.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-35923 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-35923 exists.
Sources
Also known as GHSA-xrx9-gj26-5wx9.