CVE-2026-102130

Executive Summary

CVE-2026-102130 is a code injection vulnerability (CWE-94) in the Kiteworks Email Protection Gateway in which the application fails to sufficiently validate the contents of an uploaded backup file and permits an administrator to influence how that backup is subsequently loaded. Because an authenticated administrator can manipulate the backup-loading process, they can potentially achieve arbitrary code execution on the gateway under the privileges of the underlying service account. With a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H), the flaw is remotely reachable, requires high privileges, needs no user interaction, and results in high confidentiality, integrity, and availability impact. No public proof-of-concept, exploit code, or Nuclei template exists, and there is no patch evidence from any tracked source, leaving affected deployments exposed until mitigations are applied.

Technical Analysis

The vulnerability resides in the backup-import/restore workflow of the Kiteworks Email Protection Gateway. According to the NVD description, two distinct weaknesses combine to create the exploitable condition: (1) the application "did not sufficiently validate the content of an uploaded backup," and (2) the application "allowed an administrator to influence how the application loaded it." The combination of insufficient input validation and attacker-influenced load behavior is the classic precondition for code injection (CWE-94).

The vulnerability class here is important to state precisely. CWE-94 ("Improper Control of Generation of Code") covers cases where an application constructs or processes executable content using inputs it does not adequately neutralize. In a backup-restore context this typically manifests because backup archives are treated as trusted, structured data that the application later re-materializes — for example, by deserializing embedded objects, extracting and executing scripts or configuration hooks, or restoring executable components that the service loads at startup. Because the content is not sufficiently validated, a crafted backup that deviates from the expected schema or embeds executable artifacts is accepted; because the administrator can influence the load path, the crafted artifact is then processed in a way the original developers did not intend, up to and including code execution.

The attack surface is the administrative backup upload/restore interface of the Email Protection Gateway. This is a network-reachable function (AV:N) but sits behind administrative authentication (PR:H). No user interaction is required (UI:N), which means the flaw can be triggered directly by a malicious or compromised administrator without enticing a victim. The scope is unchanged (S:U), indicating the impact is confined to the gateway and its service account rather than crossing an additional security authority boundary.

Critically, the execution context is "the underlying service account" of the gateway. This means any code executed inherits the permissions of the service that performs backup loading — an account that by necessity has read/write access to application data, configuration, and likely backup storage itself. This elevates the practical impact well beyond a simple integrity violation of an uploaded file.

No specific function names, class names, file paths, API endpoints, or parameter names are disclosed in the CVE data provided. Any claim about how the backup is parsed (for example, specific serialization formats, archive layouts, or manifest files) would be speculation and is therefore not asserted here. The technical description is limited to the vulnerability class and the observable conditions stated in the advisory: insufficient content validation plus administrator-influenced load behavior enabling potential arbitrary code execution.

Exploitation Scenarios

The following chain is inferred from the vulnerability class and the conditions stated in the NVD description. No public proof-of-concept or exploit code is available, so all steps are described at the vulnerability-class level rather than with confirmed implementation details.

1. Reconnaissance and target identification. An attacker identifies an internet-exposed Kiteworks Email Protection Gateway. This is achievable through the Shodan-style queries above (e.g., matching HTTP titles or certificate subjects associated with Kiteworks). The attacker prepares by obtaining administrative access — either legitimately (a malicious insider or a compromised admin account) or through prior credential compromise. Because the flaw requires high privileges (PR:H), the reconnaissance phase effectively includes establishing an authenticated administrative session. Notably, this is where the vulnerability is most dangerous: it turns a routine administrative capability (restoring a backup) into a code-execution primitive, which is ideal for an insider threat or an attacker who has already compromised an admin account.

2. Triggering the flaw. The attacker authenticates to the administrative interface and initiates the backup upload/restore function. Instead of uploading a legitimate backup produced by the application, they submit a crafted backup whose content is malformed or augmented relative to the expected format — specifically, content the application fails to validate. The description states administrators are allowed to "influence how the application loaded it," so the attacker also manipulates the load behavior (for example, by structuring the backup so that the application processes an attacker-controlled component during the restore).

3. Payload and execution method. At the vulnerability-class level, a CWE-94 flaw involving backup loading typically results in execution when the loaded content is interpreted as code, script, configuration, or a serialized object that the application instantiates. The payload is therefore embedded in the uploaded backup and is executed as part of the load process. Because the description explicitly states the consequence is "execute arbitrary code on the gateway as the underlying service account," the successful outcome is code running in the context of the gateway's service account. No specific payload format can be confirmed from the data available.

4. Post-exploitation impact. Once code executes as the service account, the attacker holds a foothold on the Email Protection Gateway itself. From there, typical objectives include: persistent access to the gateway; theft or tampering of email content and metadata processed by the gateway (high confidentiality and integrity impact); disruption of email protection services (high availability impact); and lateral movement or credential harvesting using the service account's access to configuration and potentially connected systems. The unchanged scope (S:U) means the immediate exploit chain does not cross an additional authorization boundary, but the compromised gateway can serve as a pivot within the broader email/security infrastructure.

Impact Assessment

CVE-2026-102130 carries a CVSS v3.1 base score of 7.2 (High) with the vector CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Each subscore is relevant to the business impact:

• AV:N (Network) — the flaw is exploitable over the network via the administrative interface, not requiring local or adjacent access. Any gateway reachable by a prospective administrator is in scope.
• AC:L (Low) — no special conditions or race windows are required; the attack is straightforward once administrative access is obtained.
• PR:H (High) — the attacker must be an authenticated administrator (or have compromised admin credentials). This constrains the threat model but does not eliminate it; insider threats, credential theft, and privilege abuse are all plausible.
• UI:N (None) — no victim interaction is needed.
• S:U (Unchanged) — impact is contained within the gateway's own security scope.
• C:H / I:H / A:H — confidentiality, integrity, and availability are all rated High, consistent with arbitrary code execution as the service account: full read of sensitive email data, full write/tamper capability, and the ability to disrupt or crash the gateway.

Blast radius is significant for any organization using the Kiteworks Email Protection Gateway. Because this component sits in the email security path, compromise potentially exposes the content of protected email, undermines the assurance the gateway is meant to provide, and can facilitate downstream attacks. The fact that the impact is realized "as the underlying service account" means the attacker operates with the gateway's own trusted identity, making malicious activity harder to distinguish from legitimate service behavior. The combination of high privilege requirement and high impact makes this particularly attractive to insider threats and to attackers who have already obtained administrative credentials — the flaw converts an existing admin foothold into full code execution on a security-critical appliance.

Detection Guidance

Detection should focus on the administrative backup upload/restore activity of the Kiteworks Email Protection Gateway. Because no public PoC exists, these rules are behavioral: they alert on anomalous backup restores and on code-execution side effects in the service-account context rather than on known signatures.

Sigma Rule

title: Suspicious Kiteworks Email Protection Gateway Backup Restore
id: 8f2c1a44-7b3e-4c9a-9d21-1a2b3c4d5e6f
status: experimental
description: Detects administrative backup upload/restore activity on the Kiteworks Email Protection Gateway that may indicate exploitation of CVE-2026-102130 (backup content validation bypass leading to code execution).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-102130
author: Threat Intelligence
date: 2026/01/01
logsource:
  product: kiteworks
  service: email_protection_gateway
detection:
  selection_action:
    action|contains:
      - 'backup_restore'
      - 'backup_upload'
      - 'restore_backup'
  selection_admin:
    user_role: 'administrator'
  condition: selection_action and selection_admin
falsepositives:
  - Legitimate administrator-initiated disaster recovery restores
level: high
tags:
  - attack.t1505
  - attack.t1190
  - cve.2026.102130

YARA Rule

rule CVE_2026_102130_Kiteworks_Backup_CodeInjection
{
    meta:
        description = "Detects potentially malicious Kiteworks Email Protection Gateway backup artifacts that may exploit CVE-2026-102130 (unvalidated backup content leading to code execution)"
        author = "Threat Intelligence"
        date = "2026-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-102130"
        cve = "CVE-2026-102130"

    strings:
        $a1 = "Kiteworks"
        $a2 = "Email Protection Gateway"
        $s1 = "backup"
        $s2 = "restore"
        $x1 = "<?php" nocase
        $x2 = "#!/bin/" nocase
        $x3 = "Runtime.getRuntime" nocase
        $x4 = "exec(" nocase
        $x5 = "eval(" nocase

    condition:
        (uint32(0) == 0x04034b50 or uint32(0) == 0x1F8B08) and
        ($a1 or $a2) and
        ($s1 or $s2) and
        1 of ($x*)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-102130 Kiteworks Email Protection Gateway Suspicious Backup Restore Upload"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"backup"; nocase; http.uri; content:"restore"; nocase; http.request_body; content:"Kiteworks"; nocase; classtype:attempted-admin; reference:cve,2026-102130; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-102130; sid:2026102130; rev:1;)

Elastic Detection

sequence by user.name with maxspan=5m
  [ authentication where event.outcome == "success" and user.roles : "administrator" ]
  [ file where event.action in ("upload", "restore") and
      file.name : ("*backup*", "*restore*") ]

Splunk SPL Query

index=kiteworks sourcetype=kiteworks:admin OR sourcetype=kiteworks:gateway
(action="backup_restore" OR action="backup_upload" OR uri="*restore*" OR uri="*backup*")
| where user_role="administrator" OR user_role="admin"
| stats count min(_time) as first_seen max(_time) as last_seen values(src_ip) as source_ips values(action) as actions by user, host
| where count > 0
| eval first_seen=strftime(first_seen,"%Y-%m-%d %H:%M:%S"), last_seen=strftime(last_seen,"%Y-%m-%d %H:%M:%S")
| sort - count

Wazuh OSSEC Rule

<group name="kiteworks,cve-2026-102130,">
  <rule id="102130" level="12">
    <decoded_as>json</decoded_as>
    <field name="product">Kiteworks</field>
    <field name="action">backup_restore|backup_upload</field>
    <description>CVE-2026-102130: Kiteworks Email Protection Gateway administrative backup restore/upload detected - possible code injection attempt</description>
    <mitre>
      <id>T1505</id>
      <id>T1190</id>
    </mitre>
  </rule>
  <rule id="102131" level="10">
    <decoded_as>json</decoded_as>
    <field name="product">Kiteworks</field>
    <field name="user_role">administrator</field>
    <field name="action">backup_restore</field>
    <description>CVE-2026-102130: Administrator-initiated backup restore on Email Protection Gateway - review for legitimacy</description>
    <mitre>
      <id>T1505</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor fix, workaround, affected version range, or patch reference is available. The guidance below is therefore risk-reduction rather than a definitive fix and should be applied in consultation with the vendor.

1. Immediate mitigations.

• Restrict administrative access to the Email Protection Gateway to the smallest possible set of trusted accounts, enforced with phishing-resistant multi-factor authentication. Because the flaw requires high privileges (PR:H), reducing and hardening the admin population directly reduces exposure.
• Do not expose the administrative interface to the public internet. Place it behind a management network or VPN/zero-trust gateway, and apply IP allow-listing so only trusted management hosts can reach the backup/restore functions.
• Treat all uploaded backups as untrusted input. Where operationally possible, disable or tightly restrict the administrative backup restore function until a fix is available, and prohibit restores sourced from anything other than backups generated by the same trusted instance.
• Validate backups out-of-band (offline) before any restore, and maintain integrity controls (checksums, signatures) over the legitimate backup chain so that tampered archives can be detected before they are loaded.
• Enable detailed audit logging of all backup upload/restore actions, capturing the acting admin, source IP, and file metadata.

2. Patch/upgrade steps.

• There is currently no published patch. Monitor the Kiteworks security advisory channel and the NVD entry (CVE-2026-102130) for a vendor fix, and apply the vendor-supplied update as soon as it becomes available. Do not rely on community or third-party patches.
• Once a fixed version is released, inventory all Email Protection Gateway instances, identify those running affected builds, and schedule upgrades through a controlled change window. Verify the fix and re-test the backup/restore workflow after upgrading.

3. Long-term hardening.

• Adopt a least-privilege model for the gateway service account so that even successful code execution is contained and cannot easily reach adjacent systems or sensitive data.
• Enforce integrity verification (signing/hashing) throughout the backup lifecycle, and require that only cryptographically authentic backups be eligible for restore.
• Segment the Email Protection Gateway from other infrastructure and monitor egress to detect unexpected outbound connections from the service account.
• Incorporate the backup-restore workflow into regular security testing (administrator-abuse scenarios and malicious-backup scenarios) so that this class of flaw is caught proactively in the future.
• Track Kiteworks advisories and subscribe to CVE/CISA feeds for timely notification of the eventual fix and any exploit developments.

References

1. NVD — CVE-2026-102130: https://nvd.nist.gov/vuln/detail/CVE-2026-102130
2. CWE-94 — Improper Control of Generation of Code ('Code Injection'): https://cwe.mitre.org/data/definitions/94.html
3. MITRE ATT&CK — T1505 Server Software Component: https://attack.mitre.org/techniques/T1505/
4. MITRE ATT&CK — T1190 Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/
5. Kiteworks security advisories (vendor channel): https://www.kiteworks.com/ — monitor for a published fix for CVE-2026-102130.

Threat actor / exploit-in-the-wild status: No public proof-of-concept, exploit code, or Nuclei template is available. CVE-2026-102130 is not listed in CISA KEV, and no exploitation in the wild has been reported. No threat actor campaigns are associated with this CVE at the time of writing.