What’s Vulnerable › Vulnerabilities

CVE-2019-3557

• Severity: critical (CVSS 9.8 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-01-15 · updated 2026-06-17
• Weakness: CWE-125

Description

The implementations of streams for bz2 and php://output improperly implemented their readImpl functions, returning -1 consistently. This behavior caused some stream functions, such as stream_get_line, to trigger an out-of-bounds read when operating on such malformed streams. The implementations were updated to return valid values consistently. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).

Affected products

• Facebook HHVM: through 3.27.4; from 3.28.0 through 3.30.0

References

• https://github.com/facebook/hhvm/commit/6e4dd9ec3f14b48170fc45dc9d13a3261765f994
• https://hhvm.com/blog/2019/01/14/hhvm-3.30.2.html
• https://github.com/facebook/hhvm/commit/6e4dd9ec3f14b48170fc45dc9d13a3261765f994
• https://hhvm.com/blog/2019/01/14/hhvm-3.30.2.html

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