Security readout for executives and security teams
Plain-English summary
This GitLab Enterprise Edition flaw could let an unauthenticated network attacker read sensitive group-related information through the merge request approvals feature. Exposed data included group names, avatars, LDAP settings, and descriptions. The issue is information disclosure, not code execution, but it can reveal organizational structure and identity-system details useful for follow-on attacks.
Executive priority
Treat this as a high-priority legacy GitLab exposure issue. It does not imply system takeover, but unauthenticated disclosure of group and LDAP metadata can materially aid reconnaissance, phishing, and identity attacks. Prioritize any internet-facing or still-operational affected GitLab EE systems.
Technical view
CVE-2018-17455 is a CWE-639 insecure direct object reference in GitLab EE merge request approvals. Affected versions are before 11.1.7, 11.2.x before 11.2.4, and 11.3.x before 11.3.1. CVSS 3.1 is 7.5: network reachable, low complexity, no privileges, no user interaction, high confidentiality impact only.
Likely exposure
Exposure is limited to GitLab Enterprise Edition deployments running the affected version ranges. Publicly reachable self-managed instances would carry higher practical risk. The source bundle does not identify affected CPEs, cloud service exposure, or whether specific configurations are required beyond the merge request approvals feature.
Exploitation context
The CVSS vector indicates unauthenticated remote exploitability for information disclosure. The provided sources do not report active exploitation, and the CVE is not marked KEV. No exploit mechanics or public exploit status are established in the supplied bundle.
Researcher notes
The supplied evidence supports an IDOR affecting merge request approvals and confidentiality only. It does not include exploit details, configuration prerequisites, or proof of exploitation. Validation should focus on version evidence, exposure history, and whether unauthorized metadata access was possible before the fixed releases.
Mitigation direction
- Upgrade GitLab EE to 11.1.7, 11.2.4, 11.3.1, or later supported versions.
- Review the GitLab security release for vendor-specific remediation guidance.
- Inventory any legacy GitLab EE instances retained for projects or archives.
- Restrict external access to outdated GitLab instances until upgraded or retired.
- Review exposed LDAP-related settings and rotate credentials only if compromise is suspected.
Validation and detection
- Confirm each GitLab EE instance version against the affected ranges.
- Verify upgrade completion to a fixed or later supported release.
- Review access logs for unusual requests around merge request approvals, if logs are retained.
- Confirm sensitive group and LDAP metadata is not readable by unauthorized users.
- Document whether any affected instances were internet-facing during the exposure window.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-639: Exact CWE lookup
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Open ATT&CK lookupCVE-2018-17455 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Source materials
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Authorization Bypass Through User-Controlled Key
Authorization Bypass Through User-Controlled Key represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.