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CVE Record

CVE-2019-1549: Fork Protection

OpenSSL 1.1.1 introduced a rewritten random number generator (RNG). This was intended to include protection in the event of a fork() system call in order to ensure that the parent and child processes did not share the same RNG state. However this protection was not being used in the default case. A partial mitigation for this issue is that the output from a high precision timer is mixed into the RNG state so the likelihood of a parent and child process sharing state is significantly reduced. If an application already calls OPENSSL_init_crypto() explicitly using OPENSSL_INIT_ATFORK then this problem does not occur at all. Fixed in OpenSSL 1.1.1d (Affected 1.1.1-1.1.1c).

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This flaw affects OpenSSL’s random number generation after a process forks. In affected versions, parent and child processes could fail to refresh fork-related RNG state by default, weakening cryptographic randomness in some applications. OpenSSL notes a timer-based partial mitigation, and the issue is fixed in OpenSSL 1.1.1d.

Executive priority

Treat this as a targeted cryptographic hygiene issue, not an emergency based on current evidence. Prioritize standard patching for internet-facing, high-trust, or fork-heavy services using affected OpenSSL versions.

Technical view

OpenSSL 1.1.1 through 1.1.1c introduced a rewritten RNG with intended fork protection, but that protection was not used by default. Applications explicitly calling OPENSSL_init_crypto() with OPENSSL_INIT_ATFORK were not affected. The risk depends on application process behavior and cryptographic use after fork().

Likely exposure

Exposure is most likely where OpenSSL 1.1.1 to 1.1.1c is present, especially in services or libraries that fork processes and rely on OpenSSL randomness after fork. Downstream Linux and vendor advisories indicate distribution-level package exposure existed.

Exploitation context

The provided sources do not show known active exploitation, and KEV is false. The issue is cryptographic weakness rather than a straightforward remote code execution path. Practical impact depends on whether affected applications fork and then generate security-sensitive random values.

Researcher notes

Focus assessment on fork behavior, OpenSSL version, and whether randomness is used for keys, nonces, sessions, or tokens after fork. Evidence does not support claiming universal compromise or active exploitation.

Mitigation direction

  • Upgrade OpenSSL to 1.1.1d or a vendor-fixed package.
  • Apply relevant Debian, Fedora, Ubuntu, Oracle, or appliance vendor updates.
  • For maintained in-house fork-based applications, verify OPENSSL_INIT_ATFORK use if upgrade is delayed.
  • Follow OpenSSL and platform vendor guidance for any product-specific remediation.

Validation and detection

  • Inventory systems and containers for OpenSSL 1.1.1 through 1.1.1c.
  • Map affected OpenSSL libraries to exposed services and fork-based workloads.
  • Confirm patched OpenSSL packages or version 1.1.1d or later are deployed.
  • Review application initialization paths for explicit OPENSSL_INIT_ATFORK where relevant.
Prepared
Confidence
high
Sources
8

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
0Timeline events
0ADP providers
16Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
OpenSSLOpenSSLFixed in OpenSSL 1.1.1d (Affected 1.1.1-1.1.1c)Listed
Weakness

CWE details

No CWE listed

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