CVE-2021-22901 Detail

Current Description

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.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  8.1 HIGH
Vector:  CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have published a CVSS score for this CVE based on publicly available information at the time of analysis. The CNA has not provided a score within the CVE List.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://curl.se/docs/CVE-2021-22901.html Exploit  Patch  Vendor Advisory 
https://github.com/curl/curl/commit/7f4a9a9b2a49547eae24d2e19bc5c346e9026479 Patch  Third Party Advisory 
https://hackerone.com/reports/1180380 Exploit  Issue Tracking  Third Party Advisory 
https://security.netapp.com/advisory/ntap-20210723-0001/
https://www.oracle.com//security-alerts/cpujul2021.html

Weakness Enumeration

CWE-ID CWE Name Source
CWE-416 Use After Free cwe source acceptance level NIST   Contributor acceptance level HackerOne  

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Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-22901
NVD Published Date:
06/11/2021
NVD Last Modified:
07/23/2021
Source:
HackerOne