Race Condition Affecting openssl Open this link in a new tab package, versions >=1.0.0, <1.0.109

  • Attack Complexity


  • User Interaction


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  • snyk-id


  • published

    2 Oct 2019

  • disclosed

    14 May 2014

  • credit


How to fix?

Upgrade OpenSSL to version 1.0.109 or higher.


OpenSSL is a SSL/TLS and Crypto toolkit. Deprecated in Mac OS and gone in iOS, this spec gives your project non-deprecated OpenSSL support.

Affected versions of this package are vulnerable to Race Condition. OepnSSL is vulnerable to denial of service (DoS) attacks through memory overwrite and client application crash. If a multithreaded client connects to a malicious server using a resumed session, it is possible to trigger a race condition in the ssl_parse_serverhello_tlsext function which allows an attacker to write up to 255 bytes of freed memory.