Use After Free Affecting curl package, versions [7.75.0,7.77.0)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
10.01% (96th percentile)

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  • Snyk IDSNYK-UNMANAGED-CURL-2317513
  • published14 Dec 2021
  • disclosed11 Jun 2021
  • creditUnknown

Introduced: 11 Jun 2021

CVE-2021-22901  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade curl to version 7.77.0 or higher.

Overview

curl is a command line tool and library for transferring data with URL syntax, supporting DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET and TFTP. libcurl offers a myriad of powerful features.

Affected versions of this package are vulnerable to Use After Free curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session ticket arrives over a connection. A malicious server can use this in rare unfortunate circumstances to potentially reach remote code execution in the client. When libcurl at run-time sets up support for TLS 1.3 session tickets on a connection using OpenSSL, it stores pointers to the transfer in-memory object for later retrieval when a session ticket arrives. If the connection is used by multiple transfers (like with a reused HTTP/1.1 connection or multiplexed HTTP/2 connection) that first transfer object might be freed before the new session is established on that connection and then the function will access a memory buffer that might be freed. When using that memory, libcurl might even call a function pointer in the object, making it possible for a remote code execution if the server could somehow manage to get crafted memory content into the correct place in memory.

CVSS Scores

version 3.1