CVE intelligence and bounded remediation
CVE-2018-6335 — A Malformed h2 frame can cause 'std::out_of_range' exception when parsing priority meta data
High
CVSS 7.5
A Malformed h2 frame can cause 'std::out_of_range' exception when parsing priority meta data. This behavior can lead to denial-of-service. This affects all supported versions of HHVM (3.25.2, 3.24.6, and 3.21.10 and below) when using the proxygen server to handle HTTP2 requests.
- Severity
- High
- CVSS
- 7.5 (3.1)
- Published
- 2018-12-31
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-400, CWE-20
Affected products
- facebook / hhvm
- facebook / hhvm / 3.24.6
- facebook / hhvm / 3.25.2
Matched remediation archetype
Resource exhaustion and denial of service
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
- Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
- Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.
Remediate safely
- Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
- Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
- Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.
Authoritative sources
Complete CVE record and remediation plan
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