UBUNTU-CVE-2021-22947

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    UBUNTU-CVE-2021-22947

    Published: 15 Sept 2021Last Modified: 27 Apr 2026
    Upstream:
    Aliases:

    Summary:

    Details: When curl >= 7.20.0 and <= 7.78.0 connects to an IMAP or POP3 server to retrieve data using STARTTLS to upgrade to TLS security, the server can respond and send back multiple responses at once that curl caches. curl would then upgrade to TLS but not flush the in-queue of cached responses but instead continue using and trustingthe responses it got *before* the TLS handshake as if they were authenticated.Using this flaw, it allows a Man-In-The-Middle attacker to first inject the fake responses, then pass-through the TLS traffic from the legitimate server and trick curl into sending data back to the user thinking the attacker's injected data comes from the TLS-protected server.

    Affected packages

    Package

    Name: curl

    Purl: pkg:deb/ubuntu/[email protected]+esm8?arch=source&distro=trusty/esm

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -7.35.0-1ubuntu2.20+esm8

    Affected versions

    7.32.0-1ubuntu1

    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
    UBUNTU-CVE-2021-22947 | CVE-DB