CVE-2022-30556 – CVE-2022-30556 is a buffer overflow vulnerabili... (How to Fix)

Q: What is the severity of CVE-2022-30556?

CVE-2022-30556 has a CVSS score of 7.5 (HIGH). CVE-2022-30556 is a buffer overflow vulnerability in Apache HTTP Server's r:wsread() function that can cause memory corruption. It affects Apache HTTP Server versions 2.4.53 and earlier. Attackers could potentially exploit this to cause denial of service or execute arbitrary code.

📋 TL;DR

CVE-2022-30556 is a buffer overflow vulnerability in Apache HTTP Server's r:wsread() function that can cause memory corruption. It affects Apache HTTP Server versions 2.4.53 and earlier. Attackers could potentially exploit this to cause denial of service or execute arbitrary code.

💻 Affected Systems

Products:

Apache HTTP Server

Versions: 2.4.0 through 2.4.53

Operating Systems: All operating systems running affected Apache versions

Default Config Vulnerable: ⚠️ Yes

Notes: All configurations using the affected r:wsread() function are vulnerable.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise, data theft, or ransomware deployment.

🟠

Likely Case

Denial of service causing Apache server crashes and service disruption.

🟢

If Mitigated

Limited impact with proper segmentation and minimal privileges, potentially just crashes.

🌐 Internet-Facing: HIGH - Apache HTTP Server is commonly internet-facing and vulnerable to unauthenticated attacks.

🏢 Internal Only: MEDIUM - Internal servers could be exploited by authenticated users or through lateral movement.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires specific conditions but is possible without authentication.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Apache HTTP Server 2.4.54 and later

Vendor Advisory: https://httpd.apache.org/security/vulnerabilities_24.html

Restart Required: Yes

Instructions:

1. Download Apache HTTP Server 2.4.54 or later from https://httpd.apache.org/download.cgi. 2. Stop the Apache service. 3. Install the new version following platform-specific instructions. 4. Restart the Apache service.

🔧 Temporary Workarounds

Disable affected modules

all

Disable modules that use the vulnerable r:wsread() function if not required.

# Check which modules are loaded
httpd -M
# Comment out LoadModule lines in httpd.conf for unnecessary modules

🧯 If You Can't Patch

Implement network segmentation to isolate Apache servers from critical systems.
Deploy web application firewall (WAF) rules to detect and block exploitation attempts.

🔍 How to Verify

Check if Vulnerable:

Check Apache version with 'httpd -v' or 'apache2 -v' and verify if it's 2.4.53 or earlier.

Check Version:

httpd -v (or apache2 -v on some systems)

Verify Fix Applied:

After patching, run 'httpd -v' or 'apache2 -v' to confirm version is 2.4.54 or later.

📡 Detection & Monitoring

Log Indicators:

Apache process crashes or abnormal restarts in system logs
Error logs containing memory corruption or segmentation fault messages

Network Indicators:

Unusual HTTP requests targeting Apache-specific functions
Traffic patterns consistent with buffer overflow exploitation

SIEM Query:

source="apache_error.log" AND ("segmentation fault" OR "memory corruption" OR "buffer overflow")

📊 Metadata

CVE ID: CVE-2022-30556

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CWE: CWE-200

Published: June 9, 2022

Last Updated: May 1, 2025

🔗 References

http://www.openwall.com/lists/oss-security/2022/06/08/7 Mailing List,Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.html Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7QUGG2QZWHTITMABFLVXA4DNYUOTPWYQ/ Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YPY2BLEVJWFH34AX77ZJPLD2OOBYR6ND/ Third Party Advisory
https://security.gentoo.org/glsa/202208-20 Third Party Advisory
https://security.netapp.com/advisory/ntap-20220624-0005/ Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/06/08/7 Mailing List,Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.html Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7QUGG2QZWHTITMABFLVXA4DNYUOTPWYQ/ Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YPY2BLEVJWFH34AX77ZJPLD2OOBYR6ND/ Third Party Advisory
https://security.gentoo.org/glsa/202208-20 Third Party Advisory
https://security.netapp.com/advisory/ntap-20220624-0005/ Third Party Advisory

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