CVE-2024-55577: Linux Ratfor Buffer Overflow Vulnerability

CVE-2024-55577 Overview

CVE-2024-55577 is a stack-based buffer overflow vulnerability in Linux Ratfor version 1.06 and earlier. Ratfor is a preprocessor that translates a structured dialect of FORTRAN into standard FORTRAN. When the tool processes a maliciously crafted input file, an attacker can trigger memory corruption on the stack and execute arbitrary code in the context of the user running Ratfor. Successful exploitation can lead to disclosure or modification of user data, or render the user environment unusable. The weakness is classified under CWE-121: Stack-based Buffer Overflow.

Critical Impact
A crafted Ratfor source file processed by a vulnerable version can achieve arbitrary code execution in the local user context, compromising confidentiality, integrity, and availability.

Affected Products

Linux Ratfor 1.06
Linux Ratfor versions prior to 1.06
Systems using the Dgate RATFOR distribution

Discovery Timeline

2025-01-15 - CVE-2024-55577 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-55577

Vulnerability Analysis

Ratfor parses source files that mix FORTRAN statements with structured control flow constructs. The vulnerable code paths copy input tokens or line data into fixed-size stack buffers without enforcing length checks. When the parser encounters an overly long identifier, string, or macro expansion, the write extends past the buffer boundary and corrupts adjacent stack memory. This overwrite can reach the saved return address or stored frame pointer.

An attacker who controls the corrupted values can redirect execution to attacker-supplied shellcode or existing gadgets. The vulnerability requires local access and user interaction, because a victim must invoke Ratfor against the malicious file. The impact spans confidentiality, integrity, and availability of the user environment.

Root Cause

The root cause is missing bounds validation on input copied into stack-allocated buffers during Ratfor lexing and preprocessing. The parser trusts that source lines and tokens will not exceed compile-time buffer sizes. Long or specially structured inputs violate that assumption and produce a classic [CWE-121] stack overflow. Refer to the JVN advisory for additional context.

Attack Vector

Exploitation requires the attacker to deliver a crafted Ratfor input file to a target user through email, shared storage, a source repository, or a build pipeline. The user must then run Ratfor against that file. There is no network-facing attack path. Because Ratfor typically runs with the invoking user's privileges, code executed through the overflow inherits those privileges and can pivot to further actions on the host.

No verified public exploit is available. The vulnerability mechanism is described in prose because no sanitized proof-of-concept has been published in the referenced advisories.

Detection Methods for CVE-2024-55577

Indicators of Compromise

Unexpected crashes or segmentation faults in the ratfor process, especially with core dumps containing non-ASCII data in return-address regions.
Ratfor processes spawning shells, network utilities, or compilers outside of expected build workflows.
Ratfor source files containing abnormally long single-line tokens, identifiers, or string literals.
Modifications to user shell configuration files or SSH keys shortly after Ratfor execution.

Detection Strategies

Inventory hosts and container images that ship ratfor binaries and correlate versions against 1.06 and earlier.
Alert on Ratfor child processes that are not expected components of the build toolchain, such as /bin/sh, curl, or wget.
Scan repositories and shared directories for .r or .ratfor files with lines exceeding typical source length thresholds.
Enable core dump collection on developer and build systems to preserve evidence of overflow attempts.

Monitoring Recommendations

Monitor process execution telemetry for ratfor invocations, including command-line arguments and parent process context.
Track file system events for new Ratfor source files arriving from external channels such as email attachments or downloads.
Log build server activity and flag Ratfor runs that terminate abnormally or produce unexpected artifacts.

How to Mitigate CVE-2024-55577

Immediate Actions Required

Restrict execution of ratfor to trusted users and remove the binary from systems that do not require it.
Treat Ratfor input files from untrusted sources as hostile and process them only inside isolated sandboxes or containers.
Audit build pipelines and continuous integration jobs that invoke Ratfor and validate the provenance of all input files.

Patch Information

No vendor patch is referenced in the NVD entry or the linked advisories at the time of publication. Consult the Dgate RATFOR project page and the JVN advisory JVNVU92217718 for updated release information. Where a fixed version is not yet available, apply the workarounds below.

Workarounds

Run Ratfor inside a non-privileged container or chroot with no network access and read-only mounts for source files.
Enforce compiler hardening flags such as -fstack-protector-strong, -D_FORTIFY_SOURCE=2, and position-independent executables when rebuilding Ratfor from source.
Enable operating-system mitigations including Address Space Layout Randomization (ASLR) and non-executable stacks on all hosts that run Ratfor.
Replace legacy Ratfor usage with maintained FORTRAN toolchains where feasible.

bash

# Configuration example: restrict and sandbox ratfor execution

# Remove world-execute permissions from the ratfor binary
sudo chmod 750 /usr/local/bin/ratfor
sudo chown root:developers /usr/local/bin/ratfor

# Run ratfor inside an unprivileged, network-isolated container
docker run --rm \
  --network=none \
  --read-only \
  --cap-drop=ALL \
  --security-opt=no-new-privileges \
  -v "$(pwd)/src:/src:ro" \
  ratfor-sandbox:latest ratfor /src/input.r

# Enable core dumps for forensic analysis of suspected exploit attempts
ulimit -c unlimited
echo '/var/crash/core.%e.%p.%t' | sudo tee /proc/sys/kernel/core_pattern