AZL-6360

    Dashboard / Vulnerabilities / AZL-6360

    AZL-6360

    Published: 11 Jun 2021Last Modified: 21 Apr 2026
    Upstream:

    Summary: CVE-2021-22901 affecting package curl for versions less than 7.76.0-5

    Details: 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.

    Affected packages

    Package

    Name: curl

    Purl: pkg:rpm/azure-linux/curl

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -7.76.0-5

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    AZL-6360 | CVE-DB