CVE-2021-3530 – CVE-2021-3530 is a stack exhaustion vulnerabili... (How to Fix)

Q: What is the severity of CVE-2021-3530?

CVE-2021-3530 has a CVSS score of 7.5 (HIGH). CVE-2021-3530 is a stack exhaustion vulnerability in GNU libiberty's rust-demangle.c that allows crafted symbols to cause denial of service through application crashes. This affects systems using GNU Binutils version 2.36 for processing Rust symbols. Organizations using affected binutils versions for compilation, debugging, or binary analysis are vulnerable.

📋 TL;DR

CVE-2021-3530 is a stack exhaustion vulnerability in GNU libiberty's rust-demangle.c that allows crafted symbols to cause denial of service through application crashes. This affects systems using GNU Binutils version 2.36 for processing Rust symbols. Organizations using affected binutils versions for compilation, debugging, or binary analysis are vulnerable.

💻 Affected Systems

Products:

GNU Binutils
GNU libiberty

Versions: GNU Binutils version 2.36

Operating Systems: Linux, Unix-like systems

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems processing Rust symbols through the demangle_path() function. Requires specific input to trigger.

📦 What is this software?

Binutils by Gnu

View all CVEs affecting Binutils →

Ontap Select Deploy Administration Utility by Netapp

View all CVEs affecting Ontap Select Deploy Administration Utility →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete denial of service through application crashes when processing malicious symbols, potentially disrupting build systems, debugging tools, or security analysis tools.

🟠

Likely Case

Application crashes when processing specially crafted Rust symbols, leading to service disruption in affected tools.

🟢

If Mitigated

Minimal impact with proper input validation and memory limits in place.

🌐 Internet-Facing: LOW - Typically requires local access or specific tool usage rather than network exposure.

🏢 Internal Only: MEDIUM - Build systems, development environments, and security tools using affected binutils could be disrupted.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires feeding crafted symbols to vulnerable applications. Proof of concept available in security advisories.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: GNU Binutils 2.36.1 and later

Vendor Advisory: https://bugzilla.redhat.com/show_bug.cgi?id=1956423

Restart Required: Yes

Instructions:

1. Update binutils package using system package manager. 2. For RedHat/CentOS: yum update binutils. 3. For Debian/Ubuntu: apt update && apt upgrade binutils. 4. Restart affected services using binutils.

🔧 Temporary Workarounds

Input validation for Rust symbols

linux

Implement input validation to reject malformed Rust symbols before processing.

# Requires custom application modifications

Resource limits

linux

Set stack size limits for applications using binutils to prevent exhaustion.

ulimit -s 8192
# Set in application startup scripts

🧯 If You Can't Patch

Isolate systems using vulnerable binutils from untrusted input sources
Implement monitoring for application crashes related to symbol processing

🔍 How to Verify

Check if Vulnerable:

Check binutils version: strings /usr/bin/objdump | grep 'GNU Binutils' | grep '2.36'

Check Version:

objdump --version | head -1

Verify Fix Applied:

Verify binutils version is 2.36.1 or later: objdump --version | head -1

📡 Detection & Monitoring

Log Indicators:

Application crashes with stack overflow errors
Segmentation faults in binutils tools

Network Indicators:

Not network exploitable

SIEM Query:

process.name: (objdump|nm|readelf) AND event.outcome: failure AND error.message: (*stack* OR *segmentation*)

📊 Metadata

CVE ID: CVE-2021-3530

CVSS v3 Score: 7.5 (HIGH)

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

CWE: CWE-674

Published: June 2, 2021

Last Updated: November 21, 2024

🔗 References

https://bugzilla.redhat.com/show_bug.cgi?id=1956423 Issue Tracking,Third Party Advisory
https://security.gentoo.org/glsa/202208-30 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210716-0006/ Third Party Advisory
https://src.fedoraproject.org/rpms/binutils/blob/rawhide/f/binutils-CVE-2021-3530.patch Patch,Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1956423 Issue Tracking,Third Party Advisory
https://security.gentoo.org/glsa/202208-30 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210716-0006/ Third Party Advisory
https://src.fedoraproject.org/rpms/binutils/blob/rawhide/f/binutils-CVE-2021-3530.patch Patch,Third Party Advisory

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