Vulnerability in ruby2.3 (UBUNTU-CVE-2024-43398)

Summary

Vulnerability in ruby2.3 (UBUNTU-CVE-2024-43398). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2.7.0-5ubuntu1.16 or later.

Original description

The description as published by the source.

REXML is an XML toolkit for Ruby. 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. The REXML gem 3.3.6 or later include the patch to fix the vulnerability.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as UBUNTU-CVE-2024-43398 has been found in ruby2.3.
Risk of unauthorized operations or information disclosure.
What to do: upgrade ruby2.3 to 2.7.0-5ubuntu1.16 or later.
If unsure, ask your IT team or search "ruby2.3 UBUNTU-CVE-2024-43398" on the vendor's site.

UBUNTU-CVE-2024-43398 (ruby2.3)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 2.7.0-5ubuntu1.16 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in ruby2.3.

📍 Affected scope

Check the vendor advisory for the affected versions of ruby2.3.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 2.7.0-5ubuntu1.16.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'ruby2.3' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'ruby2.3' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で ruby2.3 を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade ruby2.3 to 2.7.0-5ubuntu1.16
```
ステージング環境で 2.7.0-5ubuntu1.16 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Ubuntu:Pro:16.04:LTS ruby2.3

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:Pro:18.04:LTS ruby2.5

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:20.04:LTS ruby2.7

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.7.0-5ubuntu1.16"}]}]

Ubuntu:22.04:LTS ruby3.0

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.2-7ubuntu2.10"}]}]

Ubuntu:24.04:LTS ruby3.2

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.3-1ubuntu0.24.04.5"}]}]

References

advisory ubuntu.com
advisory ubuntu.com
report ubuntu.com
report cve.org
report github.com