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Use After Free


Severity High
Score 7.5/10


A flaw was found in glibc. In an extremely rare situation, the "getaddrinfo" function may access memory that has been freed, resulting in an application crash. This issue is only exploitable when a NSS module implements only the "_nss_*_gethostbyname2_r" and "_nss_*_getcanonname_r" hooks without implementing the "_nss_*_gethostbyname3_r" hook. The resolved name should return a large number of IPv6 and IPv4, and the call to the getaddrinfo function should have the AF_INET6 address family with AI_CANONNAME, AI_ALL and AI_V4MAPPED as flags.

  • LOW
  • NONE
  • NONE
  • NONE
  • NONE
  • HIGH

CWE-416 - Use After Free

Use-after-free (UaF) vulnerability occurs when the application is using a pointer to memory that has been freed. Any attempt to read/write to a buffer after it is de-allocated allows memory corruption, sensitive information exposure, and can potentially lead to arbitrary code execution.

Advisory Timeline

  • Published