Atomicorp WAF Research Note: CVE-2017-12635

Apache CouchDB 1.7.0 / 2.x < 2.1.1 - Remote Privilege Escalation

Research Notes

This page documents research related to exploit techniques, attack behaviors, testing results, and WAF rule interactions associated with this vulnerability.

Research finding: this note documents observed WAF protections relevant to exploit techniques associated with this vulnerability.

These notes are not intended to represent the full set of vulnerabilities mitigated by Atomicorp products and should not be interpreted as a coverage matrix, certification list, or census of protected CVEs.

Atomicorp WAF protections are primarily designed around attack techniques and exploit behaviors rather than individual vulnerability identifiers. A published research note documents a positive research finding related to that CVE. If a CVE is absent from these notes, no conclusion should be drawn about protection status.

Vulnerability Description

Due to differences in the Erlang-based JSON parser and JavaScript-based JSON parser, it is possible in Apache CouchDB before 1.7.0 and 2.x before 2.1.1 to submit _users documents with duplicate keys for ‘roles’ used for access control within the database, including the special case ‘_admin’ role, that denotes administrative users. In combination with CVE-2017-12636 (Remote Code Execution), this can be used to give non-admin users access to arbitrary shell commands on the server as the database system user. The JSON parser differences result in behaviour that if two ‘roles’ keys are available in the JSON, the second one will be used for authorising the document write, but the first ‘roles’ key is used for subsequent authorization for the newly created user. By design, users can not assign themselves roles. The vulnerability allows non-admin users to give themselves admin privileges.

Public Vulnerability References

CVE Details

CVE: CVE-2017-12635
Name: Apache CouchDB 1.7.0 / 2.x < 2.1.1 - Remote Privilege Escalation
Severity: critical
CVSS: 9.8 (Critical)
CVSS source: N/A
Vendor: apache
Product: couchdb
Latest protected observation: 2026-07-03
Rule IDs observed: 392301

Test or Research Source

Source: http/cves/2017/CVE-2017-12635.yaml
Tags: apache, couchdb, cve, cve2017, intrusive, vkev, vuln

Research Note Context

This research note documents exploit-technique analysis associated with this vulnerability and references Atomicorp WAF protections observed during engineering review, testing, or validation activities.

Atomicorp security controls are generally designed to identify and mitigate attack techniques and exploit behaviors rather than individual CVE identifiers. As a result, protections developed for one vulnerability may also apply to related attack variants and future vulnerabilities using similar techniques.

Learn More

Atomicorp develops commercially supported security technologies for web applications, servers, endpoints, workloads, and legacy enterprise platforms.

Organizations interested in protecting systems against exploit techniques associated with vulnerabilities such as this one can learn more about:

Atomic ModSecurity Rules: commercially maintained WAF rules for ModSecurity deployments, including protections for web attacks, bots, scanners, malware, exploitation attempts, and emerging vulnerability classes.
Atomic WAF: an enterprise web application firewall with Atomicorp rules, centralized management, reporting, authentication controls, and operational tooling.
Atomic ModSecurity Integrator: a special licensing option for MSPs, MSSPs, OEMs, VARs, reverse proxy providers, and other integrators who want to incorporate Atomicorp ModSecurity rule technology into their own products or services.
Atomic OSSEC: an enterprise OSSEC-based intrusion detection, compliance, and security monitoring platform.
Atomic Protector: workload protection for Linux, web, cloud, data center, and hybrid environments.

For additional information, product evaluations, or technical discussions, visit https://www.atomicorp.com/ or https://modsecurity.io/ .