Package Instance

REXML ReDoS vulnerability
### Impact

The REXML gem before 3.3.9 has a ReDoS vulnerability when it parses an XML that has many digits between `&#` and `x...;` in a hex numeric character reference (`&#x...;`).

This does not happen with Ruby 3.2 or later. Ruby 3.1 is the only affected maintained Ruby. Note that Ruby 3.1 will reach EOL on 2025-03.

### Patches

The REXML gem 3.3.9 or later include the patch to fix the vulnerability.

### Workarounds

Use Ruby 3.2 or later instead of Ruby 3.1.

### References

* https://www.ruby-lang.org/en/news/2024/10/28/redos-rexml-cve-2024-49761/: An announce on www.ruby-lang.org

REXML has DoS condition when parsing malformed XML file
The REXML gems from 3.3.3 to 3.4.1 have a DoS vulnerability when parsing XML containing multiple XML declarations.
If you need to parse untrusted XMLs, you may be impacted to these vulnerabilities.

REXML denial of service vulnerability
### Impact

The REXML gem before 3.3.6 has a DoS vulnerability when it parses an XML that has many deep elements that have same local name attributes.

If you need to parse untrusted XMLs with tree parser API like `REXML::Document.new`, you may be impacted to this vulnerability. If you use other parser APIs such as stream parser API and SAX2 parser API, this vulnerability is not affected.

### Patches

The REXML gem 3.3.6 or later include the patch to fix the vulnerability.

### Workarounds

Don't parse untrusted XMLs with tree parser API.

### References

* https://www.ruby-lang.org/en/news/2024/08/22/dos-rexml-cve-2024-43398/ : An announce on www.ruby-lang.org