Security readout for executives and security teams
Plain-English summary
Buck is a build tool. This CVE means a maliciously crafted parser-cache state file could make Buck run attacker-controlled code when it deserializes that state. The issue is critical because successful exploitation could affect confidentiality, integrity, and availability of build systems.
Executive priority
Treat this as urgent for teams using legacy Buck in build or CI systems. Build infrastructure often has code, secrets, and deployment access, so compromise can have broader business impact even if the affected component is not internet-facing.
Technical view
Buck's parser-cache command loaded and saved state using Java serialized objects. Maliciously crafted state information could lead to code execution during deserialization. The issue is classified as CWE-502 and scored CVSS 3.1 9.8. Sources state Buck versions before v2018.06.25.01 are affected.
Likely exposure
Exposure is most likely in developer or CI environments using Facebook Buck before v2018.06.25.01, especially where parser-cache state can be shared, restored, or influenced by untrusted sources. The provided sources do not identify other affected products.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Risk comes from unsafe Java deserialization in a build-tool workflow where malicious state data is loaded by the parser-cache command.
Researcher notes
Evidence is concise: CVE text, CVSS metadata, CWE-502 classification, and an upstream commit reference. The sources do not provide exploit details, observed exploitation, or broad ecosystem impact. Validation should focus on version inventory and cache trust boundaries.
Mitigation direction
- Upgrade Buck to v2018.06.25.01 or later.
- Remove parser-cache state created by untrusted or unknown sources.
- Restrict write access to build cache and CI workspace state.
- Check the upstream Buck commit and release guidance before deploying changes.
Validation and detection
- Inventory Buck versions used by developers and CI runners.
- Confirm no systems run Buck versions earlier than v2018.06.25.01.
- Review CI cache restoration paths for untrusted parser-cache state.
- Verify build cache directories are writable only by trusted principals.
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-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2018-6331 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/facebook/buck/commit/8c5500981812564877bd122c0f8fab48d3528ddfCVE 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.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.