Security readout for executives and security teams
Plain-English summary
CVE-2021-29506 is a denial-of-service risk in GraphHopper. A vulnerable Navigate endpoint can process attacker-influenced regular expressions in a way that may exhaust resources and disrupt routing availability. It affects GraphHopper versions 2.0 through before 2.4, and the sources state fixes are available in 2.4 and 3.0.
Executive priority
Treat this as a moderate availability risk. It is most urgent for organizations whose routing service is business-critical or externally reachable. Prioritize upgrade during the next normal security maintenance window unless monitoring shows instability or the endpoint has broad user access.
Technical view
The issue is described as regular expression injection in GraphHopper’s Navigate endpoint, mapped to CWE-400. CVSS 3.1 is 6.5, with network access, low attack complexity, low privileges, no user interaction, no confidentiality or integrity impact, and high availability impact.
Likely exposure
Exposure is most likely where GraphHopper 2.0 to before 2.4 is deployed and the Navigate endpoint is reachable by users with low privileges. The provided sources do not identify managed services, downstream products, or specific deployment configurations beyond GraphHopper itself.
Exploitation context
The CVE is not listed as KEV in the provided bundle, and the cited sources do not state active exploitation. The CVSS vector indicates the issue is network reachable, low complexity, and requires low privileges, with denial of service as the main impact.
Researcher notes
The source bundle provides affected versions, CVSS, CWE, advisory, PR, and fix commit. It does not provide evidence of exploitation in the wild, a detailed operational workaround, or affected downstream products. Avoid expanding scope beyond GraphHopper without separate evidence.
Mitigation direction
- Upgrade affected GraphHopper deployments to version 2.4, 3.0, or later vendor-supported releases.
- Review the GitHub advisory and fix PR before relying on any backported patch.
- Limit access to the Navigate endpoint where business requirements allow.
- Monitor routing service availability and resource consumption for abnormal spikes.
- Check vendor guidance if running a fork or distribution with custom patches.
Validation and detection
- Inventory GraphHopper versions across production, staging, containers, and build dependencies.
- Confirm no running deployment uses GraphHopper >=2.0 and <2.4.
- Verify the Navigate endpoint is not exposed beyond intended authenticated users.
- Review dependency lockfiles and container images for vulnerable GraphHopper versions.
- Confirm remediation by matching deployed builds to the patched release or fix commit.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-29506 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
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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:L/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/graphhopper/graphhopper/security/advisories/GHSA-hf44-3mx6-vhhwCVE reference · x_refsource_CONFIRM
- https://github.com/graphhopper/graphhopper/pull/2304CVE reference · x_refsource_MISC
- https://github.com/graphhopper/graphhopper/commit/eb189be1fa7443ebf4ae881e737a18f818c95f41CVE reference · x_refsource_MISC
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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.