CVE-2025-11083: GNU Binutils Buffer Overflow Vulnerability

CVE-2025-11083 Overview

CVE-2025-11083 is a heap-based buffer overflow [CWE-119] in GNU Binutils 2.45. The flaw resides in the elf_swap_shdr function within the bfd/elfcode.h library, which is part of the linker component. An attacker with local access and low privileges can trigger the overflow by supplying a crafted ELF (Executable and Linkable Format) file for processing. The exploit code has been publicly disclosed, increasing the risk of opportunistic use against systems that parse untrusted binaries. The maintainers have addressed the issue in Binutils 2.46 via commit 9ca499644a21ceb3f946d1c179c38a83be084490.

Critical Impact
Local attackers can trigger heap corruption in the Binary File Descriptor (BFD) library when processing malformed ELF section headers, potentially leading to limited confidentiality, integrity, and availability impact on affected hosts.

Affected Products

GNU Binutils 2.45
Downstream tools that link against the BFD library (ld, objdump, readelf, nm, strip)
Siemens products bundling affected Binutils versions (see Siemens Security Advisory SSA-082556)

Discovery Timeline

2025-09-27 - CVE-2025-11083 published to the National Vulnerability Database (NVD)
Patch - Commit 9ca499644a21ceb3f946d1c179c38a83be084490 merged into the binutils-gdb repository; fix scheduled for Binutils 2.46
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-11083

Vulnerability Analysis

The vulnerability is a heap-based buffer overflow in elf_swap_shdr, a helper routine in bfd/elfcode.h responsible for byte-swapping ELF section header entries when the BFD library parses object files. This routine is invoked by any Binutils tool that reads ELF binaries, including ld, objdump, readelf, and nm. When the function processes an ELF file containing malformed section header metadata, it writes past the bounds of a heap-allocated buffer.

The overflow occurs during local processing of attacker-controlled input files. The impact is bounded because exploitation requires local access with low privileges and user interaction is not needed only for the tool invocation. Successful triggering can corrupt adjacent heap structures, cause tool crashes, or in some scenarios enable further memory manipulation. See Sourceware Bug Report #33457 for the reproducer and maintainer discussion.

Root Cause

The root cause is insufficient bounds validation when elf_swap_shdr swaps and copies section header fields from a crafted ELF file into an internal BFD structure. The code trusts size or count fields from the input without adequate sanity checks, producing an out-of-bounds write on the heap. This is a classic instance of [CWE-119] — improper restriction of operations within the bounds of a memory buffer.

Attack Vector

Exploitation requires an attacker to place a specially crafted ELF file on the target system and induce a local user or automated process to run a Binutils tool against it. Common trigger paths include build pipelines that run objdump or readelf on artifacts of untrusted origin, package inspection workflows, and forensic analysis of unknown binaries. Because the attack surface is local and the vulnerability produces bounded impact, remote exploitation is not applicable. Refer to the Sourceware Git Commit Reference for the exact code change that closes the flaw.

Detection Methods for CVE-2025-11083

Indicators of Compromise

Unexpected crashes, segmentation faults, or heap corruption abort messages from Binutils tools (ld, objdump, readelf, nm, strip) during build or analysis workflows
Core dumps generated by Binutils processes referencing elf_swap_shdr or bfd/elfcode.h in stack traces
Presence of unexplained ELF files with malformed section header tables in build directories, temp folders, or user home directories

Detection Strategies

Query package inventories and file version metadata to identify hosts running GNU Binutils 2.45 or earlier
Enable AddressSanitizer or run Binutils under a memory-error detector such as Valgrind in CI environments to surface heap overflows when processing new binaries
Alert on Binutils processes that terminate abnormally (SIGSEGV, SIGABRT) via host telemetry

Monitoring Recommendations

Log invocations of Binutils utilities against files sourced from untrusted locations, including web downloads and shared upload directories
Monitor CI/CD build agents for crashes in linking or binary inspection stages, which are common execution paths for BFD parsing
Track deployment of Binutils updates across Linux fleets using configuration management tooling to confirm the fixed 2.46 release is present

How to Mitigate CVE-2025-11083

Immediate Actions Required

Inventory all systems running GNU Binutils 2.45 and prioritize build servers, developer workstations, and forensic analysis hosts
Restrict execution of Binutils tools against ELF files originating from untrusted sources until patched
Apply the upstream patch 9ca499644a21ceb3f946d1c179c38a83be084490 or upgrade to Binutils 2.46 when available from your distribution

Patch Information

The fix is committed in the binutils-gdb repository as commit 9ca499644a21ceb3f946d1c179c38a83be084490 and is included in Binutils 2.46. Users of Linux distributions should track vendor backports. Industrial and OT operators using Siemens products that embed Binutils should review Siemens Security Advisory SSA-082556 for product-specific guidance.

Workarounds

Avoid running Binutils utilities on ELF files of unknown provenance until patched versions are deployed
Sandbox Binutils invocations in CI pipelines using containers or seccomp profiles to contain the impact of a crash or heap corruption
Limit local user access on shared build infrastructure to reduce the pool of principals capable of introducing malicious ELF inputs

bash

# Verify installed Binutils version and update on Debian/Ubuntu
dpkg -l | grep binutils
sudo apt update && sudo apt install --only-upgrade binutils

# Verify installed Binutils version and update on RHEL/Fedora
rpm -q binutils
sudo dnf upgrade binutils

# Build from source with the upstream fix
git clone git://sourceware.org/git/binutils-gdb.git
cd binutils-gdb
git checkout 9ca499644a21ceb3f946d1c179c38a83be084490
./configure && make && sudo make install