Security readout for executives and security teams
Plain-English summary
CVE-2018-6343 is a denial-of-service flaw in Facebook Proxygen. A remote, unauthenticated network interaction can trigger a crash when Proxygen handles certain HTTP/2 certificate-related frames over fizz TLS 1.3 transport. The known impact is service availability, not data theft or modification.
Executive priority
Treat this as a high-priority availability risk for services relying on affected Proxygen builds. The business concern is outage potential on exposed HTTP/2 TLS services. Prioritize confirming exposure and moving affected deployments to the fixed release.
Technical view
Proxygen dereferences a secondary auth manager without first validating that it is set, a CWE-476 null pointer issue. The CVE states this occurs while parsing Certificate or CertificateRequest HTTP/2 frames over fizz transport. Affected releases start at v2018.10.29.00 and are fixed in v2018.11.19.00.
Likely exposure
Exposure is likely limited to systems embedding or deploying Facebook Proxygen versions from v2018.10.29.00 before the fixed v2018.11.19.00 release, especially where HTTP/2 over fizz TLS 1.3 is enabled. Systems not using Proxygen or that transport path are unlikely to be affected.
Exploitation context
The CVSS vector indicates remote, unauthenticated, low-complexity availability impact. The source bundle does not show CISA KEV listing or cited evidence of active exploitation, so active exploitation should not be assumed.
Researcher notes
The root cause is a missing validation before dereferencing the secondary auth manager. Available sources identify the affected version window and fixing commit, but do not provide exploit telemetry, broad product impact, or alternate mitigations beyond updating and checking vendor guidance.
Mitigation direction
- Upgrade Proxygen to v2018.11.19.00 or later where applicable.
- Identify downstream products or services bundling vulnerable Proxygen releases.
- Review vendor or maintainer guidance for any deployment-specific mitigations.
- Prioritize externally reachable HTTP/2 services using fizz TLS 1.3 transport.
Validation and detection
- Inventory Proxygen versions in source, packages, containers, and deployed artifacts.
- Confirm whether affected services use fizz TLS 1.3 transport with HTTP/2.
- Compare local Proxygen code against the referenced fixing commit.
- Review crash telemetry for certificate-frame parsing failures or null dereference signatures.
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-476: 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-2018-6343 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: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:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary 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:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/facebook/proxygen/commit/0600ebe59c3e82cd012def77ca9ca1918da74a71CVE 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.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.