CVE-2022-46293

Executive Summary

CVE-2022-46293 is a critical remote code execution vulnerability in Open Babel 3.1.1 and master commit 530dbfa3, stemming from multiple out-of-bounds write vulnerabilities in the translationVectors parsing functionality within the MOPAC file format, specifically in the "Final Point and Derivatives" section. The vulnerability carries a CVSS score of 9.8, indicating critical severity with high impact on confidentiality, integrity, and availability. An attacker can craft a malformed file to trigger arbitrary code execution, and no patch is currently available from any tracked source.

Technical Analysis

The vulnerability resides in the MOPAC (Molecular Orbital PACkage) file format parsing component of Open Babel, a widely used chemical informatics toolbox that converts between over 100 molecular file formats. The NVD description identifies the flaw as existing within the "translationVectors parsing functionality" inside the "Final Point and Derivatives" section of the MOPAC format parser.

The vulnerability is classified as multiple out-of-bounds write conditions. When parsing the Final Point and Derivatives section, the parser fails to perform adequate bounds checking on translation vector arrays. A specially-crafted malformed MOPAC file can cause the parser to write data beyond the allocated buffer boundaries, leading to memory corruption. This memory corruption can potentially be leveraged to achieve arbitrary code execution — the highest-impact consequence of memory corruption flaws.

The attack surface is significant because Open Babel is frequently deployed in batch processing environments, web-based chemical file conversion services, and automated research pipelines. The library is also integrated into numerous chemistry and bioinformatics tools, meaning malicious files can be delivered through email attachments, uploaded to web services, or included in shared research datasets.

The out-of-bounds write occurs during parsing of the translation vector coordinates. The "Final Point and Derivatives" section within the MOPAC format typically contains energy values, gradients, and translation vectors. Insufficient validation of the count or coordinates of these vectors permits heap or stack overflow conditions, depending on how Open Babel allocates the workspace buffers.

The CVSS vector reflects a network-exploitable vulnerability (AV:N) requiring no privileges (PR:N) and no user interaction (UI:N), although in practice file-based exploitation often requires the target to open a malicious file (which adjusts the realistic attack scenario). The scope is unchanged (S:U), but the impact scores are all high (C:H/I:H/A:H) because memory corruption leading to arbitrary code execution compromises the entire process.

No patch is available from any tracked source. The CNA has not released a vendor fix, no workarounds are documented, and there is no evidence of a patch in any major distribution or upstream repository. EPSS score of 0.00850 (54.8th percentile) suggests low current exploitation probability.

Exploitation Scenarios

The attack chain for CVE-2022-46293 proceeds as follows:

Step 1: Reconnaissance and Target Identification

Target identification focuses on systems that process untrusted MOPAC files. This includes:

• Chemistry research environments where scientists share MOPAC calculation results
• Web-based molecular format conversion services
• Automated high-throughput screening pipelines
• API endpoints that accept user-uploaded chemical files

An attacker may identify these targets through Shodan searches for Open Babel web services, or by targeting specific research institutions and pharmaceutical organizations known to use computational chemistry tools.

Step 2: Triggering the Vulnerability

The attacker crafts a malicious MOPAC file with a malformed "Final Point and Derivatives" section. Specifically, the translationVectors data within this section is manipulated to contain values that exceed expected bounds or count quantities that mismatch the expected allocation size. When Open Babel 3.1.1 parses this file, the out-of-bounds write is triggered during the translationVectors parsing routine.

Importantly, the parsing of a .mop file into any target format will trigger the vulnerable code path. This means the attacker does not need to know the output format — any conversion operation that reads a MOPAC file exposes the attack surface.

Step 3: Payload Execution

No public PoC is available, so the attack chain is inferred from the vulnerability class. For an out-of-bounds write in a parser, the standard exploitation technique involves:

• Heap grooming to control adjacent memory allocations
• Overwriting adjacent heap metadata (e.g., chunk headers) to achieve arbitrary write
• Abstracting that into arbitrary code execution via function pointer overwrite or vtable corruption
• Alternatively, overwriting stack return addresses if the overflow occurs in stack-allocated buffers

The payload would typically be a multi-stage shellcode that establishes persistence or an interactive reverse shell on the compromised system.

Step 4: Post-Exploitation Impact

Upon successful exploitation, the attacker gains code execution in the context of the Open Babel process. In a typical batch processing server, this would be a service account with access to input/output directories. In a web service, this could lead to:

• Exfiltration of proprietary research data
• Lateral movement to connected research databases
• Ransomware deployment on research infrastructure
• Persistent backdoor installation for long-term access

Given the critical CVSS score of 9.8, the vulnerability is considered exploitable with trivial complexity and no specialized conditions.

Impact Assessment

Business Impact: Critical. CVE-2022-46293 enables remote code execution with no authentication requirements. Organizations in pharmaceutical research, chemical engineering, and academic chemistry face direct business risk from data theft and system compromise. The lack of patch availability elevates this from a routine vulnerability to a permanent attack surface that requires compensating controls.

Affected Systems: Open Babel 3.1.1 and master commit 530dbfa3. Given the MOPAC format is one of many supported by Open Babel, any deployment that processes MOPAC files is vulnerable. This includes scientific computing clusters, web-based conversion tools, and desktop chemistry workstations.

Blast Radius: The vulnerability propagates to all downstream systems that receive converted files. If a conversion service is compromised, the attacker gains the ability to serve malicious files to all service users, creating a supply-chain style propagation vector. The final derivatives parsing logic is used in every MOPAC conversion, meaning all users of vulnerable Open Babel versions are at risk.

CVSS Analysis: The 9.8 score reflects network attack vector, low complexity, no privileges required, no user interaction, and non-changing scope with high confidentiality, integrity, and availability impact. This places CVE-2022-46293 in the critical severity band.

Detection Guidance

The following detection rules target the exploitation of CVE-2022-46293. Given the file-based nature of the attack, detection focuses on process-level anomalies during file conversion, abnormal file content patterns, and network signatures of exploit attempts.

Sigma Rule

title: Open Babel MOPAC TranslationVectors Out-of-Bounds Write Attempt
id: 3f7a9c12-7d54-4e8b-bc89-53a1f2d8e4c6
status: experimental
description: Detects anomalous Open Babel process behavior consistent with CVE-2022-46293 exploitation
author: Valters IT Security Research
date: 2024-01-15
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\obabel.exe'
        CommandLine|contains|all:
            - '\.mop'
            - '-O'
    filter:
        CommandLine|contains: '--sdf'
    condition: selection and not filter
level: high
tags:
    - attack.t1203
    - cve.2022.46293
falsepositives:
    - Legitimate MOPAC to SDF conversions
    - Batch processing scripts automating MOPAC calculations

YARA Rule

rule CVE_2022_46293_MOPAC_TranslationVectors {
    meta:
        author = "Valters IT Security Research"
        description = "Detects potentially malicious MOPAC files targeting Open Babel translationVectors parsing"
        cve = "CVE-2022-46293"
        severity = "critical"
    strings:
        $mopac_header = "FINAL POINT AND DERIVATIVES" ascii wide
        $tv_section = "T" ascii
        $numeric_pattern = /[-+]?\d+\.\d{6,}/
        $large_coordinate = /[-+]?\d{10,}\.\d+/
    condition:
        $mopac_header and $tv_section and $numeric_pattern and (
            #large_coordinate > 20 or
            filesize > 500000
        )
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2022-46293 Open Babel MOPAC Upload Attempt";
flow:established,to_server;
content:".mop"; http_uri; nocase;
content:"filedata"; http_uri; nocase;
pcre:"/filename.*\.mop/i";
metadata:attack_target Server, deployment Perimeter, signature_severity Critical, created_at 2024_01_15;
sid:2022046293; rev:1;)

Elastic Detection

// Detect rapid abnormal termination of obabel processes
sequence with maxspan=10m
    [process where event.type == "start" and process.name == "obabel.exe" and 
     process.args : ("*.mop", "*.MOP")]
    [process where event.type == "end" and process.exit_code == -1073740791] // 0xC0000409
// 0xC0000409 = STATUS_STACK_BUFFER_OVERRUN

// Alternative: file creation followed by process crash
sequence with maxspan=5m
    [file where event.type == "creation" and file.extension in ("mop", "MOP")]
    [process where process.name == "obabel.exe" and process.exit_code != 0]

Splunk SPL Query

index=windows OR index=linux sourcetype=ProcessRollup2 OR sourcetype="WinEventLog:Security"
| search (process_name="obabel.exe" OR process_name="babel.exe") 
    AND (command_line="*.mop*" OR command_line="*.MOP*")
| eval is_suspicious_crash = case(
    exit_code == "-1073740791" OR exit_code == "-1073741819", "CRITICAL - Buffer Overrun",
    exit_code != "0" AND exit_code != "", "Abnormal Exit",
    true(), "Normal")
| stats count by host, is_suspicious_crash, process_name, parent_process_name
| where is_suspicious_crash != "Normal"

# Also detect high-volume file upload web requests with .mop extension
index=web sourcetype=access_combined 
| search uri_path="*mop*" OR filename="*.mop*" 
| stats count by clientip, uri_path, status
| where count > 50

Wazuh OSSEC Rule

<group name="openbabel,">
  <rule id="100402" level="12">
    <if_sid>500</if_sid>
    <field name="win.eventdata.image">.*obabel.exe</field>
    <field name="rule.description">obabel</field>
    <match>exit code|terminated|crash|core dumped</match>
    <description>CVE-2022-46293: Open Babel process crash - possible translationVectors out-of-bounds write exploitation attempt</description>
    <group>attack.t1203,</group>
    <options>no_full_log</options>
  </rule>

  <rule id="100403" level="10">
    <if_sid>100402</if_sid>
    <field name="win.eventdata.commandLine">.*\.mop.*</field>
    <description>CVE-2022-46293: Open Babel crash while processing MOPAC file - high confidence exploitation indicator</description>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 0/4 — UNPATCHED

No patch is available from any tracked source for CVE-2022-46293. The upstream project has not released a fixed version, and no third-party or distribution-specific patches have been identified. Organizations must rely entirely on compensating controls.

1) Immediate Mitigations (Days 1-14):

• Restrict Open Babel processing to trusted internal sources only
• Disable MOPAC format support in web-facing conversion services if architecture allows (e.g., via format whitelist filtering)
• Use file type detection that validates MOPAC file structure before passing to Open Babel
• Deploy Open Babel instances in isolated container environments with read-only filesystem access and no network egress
• Apply minimum required privileges to Open Babel processes (dedicated low-privilege service account)
• Deploy usermode sandboxing (e.g., seccomp-bpf, AppArmor, SELinux) to limit syscall surface

2) Patch/Upgrade Steps:

• Monitor the Open Babel GitHub repository and mailing lists for security releases
• Subscribe to NVD/CISA notifications for CVE-2022-46293 status changes
• When a patch becomes available, test update in staging environment first
• Apply patched version to all production systems within 72 hours of release
• If Open Babel is embedded in third-party tools, coordinate with the vendor for an updated integration

3) Long-Term Hardening:

• Replace Open Babel with actively maintained alternatives for MOPAC processing where feasible
• Implement a file sanity-checking layer (e.g., using Open Babel's own data structures in a pre-validation pass) to reject anomalous files
• Enforce the principle of least privilege across all scientific toolchains — no scientific conversion service should run as root or administrator
• Establish a vulnerability management SLA for scientific computing tools (these are often overlooked by standard patch management programs)
• Deploy application allowlisting on servers hosting scientific conversion services
• For high-value research environments, isolate batch conversion workloads from core analytical systems and research data stores

References

1. NVD Entry — CVE-2022-46293: https://nvd.nist.gov/vuln/detail/CVE-2022-46293
2. Open Babel Project — Official Repository: https://github.com/openbabel/openbabel
3. Open Babel Documentation — MOPAC Format Support: https://openbabel.org/docs/dev/FileFormats/MOPAC_cartesian_format.html
4. CISA Known Exploited Vulnerabilities Catalog (CVE-2022-46293 NOT listed): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
5. FIRST EPSS Scoring for CVE-2022-46293: https://www.first.org/epss/

Threat Actor Activity: No public evidence exists of active exploitation campaigns leveraging CVE-2022-46293 at the time of this report. The EPSS score of 0.00850 (54.8th percentile) indicates low current exploit probability, but the lack of hotfix reduces confidence. The vulnerability class (out-of-bounds write in a scientific data parser) is a historically well-trodden path for cybercriminal and espionage groups targeting research institutions. Organizations in the pharmaceutical and chemical sectors should treat this as a high-priority latent risk given the extended unpatched window, as exploit code will likely surface once reverse engineering of the vulnerable parsing routine completes.