| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| When performing transfers via libcurl’s multi interface, pooled TLS
connections can outlive their originating easy handles. In OpenSSL 3 provider
configurations, libcurl attaches an allocated library context to the easy
handle's state and passes it to OpenSSL without acquiring an ownership
reference; destroying the easy handle prematurely frees this context while the
active connection retains a dangling pointer, leading to a heap-use-after-free
upon subsequent I/O or post-handshake operations. |
| When `CURLOPT_PINNEDPUBLICKEY` is configured alongside options that disable
standard peer verification (`CURLOPT_SSL_VERIFYPEER = 0` and
`CURLOPT_SSL_VERIFYHOST = 0`), libcurl fails to enforce public key pinning on
connections established without a presented server certificate. Bypassing the
pinning check under these disabled-verification conditions allows
unauthenticated connections to succeed when they should be rejected. |
| A flaw in libcurl makes it wrongly reuse an existing HTTPS connection setup
for a given hostname even when using a different Native CA Store setting
(`CURLSSLOPT_NATIVE_CA`) than when the connection was created. |
| A `Set-Cookie:` header using tab (horizontal tab, ASCII code 9) instead of
space (ascii code 32) immediately before the `Secure` attribute causes curl to
store the cookie without its Secure flag. The cookie might then wrongfully be
sent over plaintext HTTP on subsequent requests to the same host. |
| With the wolfSSL backend, when CA caching is enabled and an
`CURLOPT_SSL_CTX_FUNCTION` callback replaces the trust store, libcurl can
silently reinstall the cached store after the callback returns. A certificate
trusted by the cached store but rejected by the callback-selected store is
then incorrectly accepted. |
| When libpsl support is enabled, libcurl fails to enforce the Public Suffix
List boundary check when processing a `Set-Cookie` header where the `Domain`
attribute explicitly matches an origin host that is itself a public suffix
(e.g., `Domain=co.uk` set by `co.uk`).
Instead of coercing it into a strict host-only cookie, libcurl saves the
cookie with wildcard domain scope (`.co.uk`). Consequently, the cookie is
inappropriately included in subsequent outbound requests or HTTP redirects to
arbitrary sibling subdomains under the same public suffix (e.g.,
`attacker.co.uk`). |
| A flaw in libcurl's handling of HTTP/2 Server Push streams, when the parent
handle is set to share connections with other handles, can lead to
use-after-free in the cleanup process. |
| A flaw in the libcurl SASL negotiation for LDAP authentication allows an
incomplete handshake sequence to be misinterpreted as a successful
cryptographic verification. An attacker executing a Man-in-the-Middle (MITM)
attack can inject a premature or shortcut response that bypasses complete peer
validation. |
| A use-after-free vulnerability exists in libcurl when an application
configures an HTTP/2 stream-dependency tree via `CURLOPT_STREAM_DEPENDS` or
`CURLOPT_STREAM_DEPENDS_E`, subsequently invokes `curl_easy_reset()`, and
finally terminates the handle with `curl_easy_cleanup()`. During this final
cleanup phase, libcurl attempts to access and modify an internal structure
that was already freed during the reset operation. |
| libcurl keeps previously used connections in a connection pool for subsequent
transfers to reuse if one of them matches the setup.
An easy handle that first uses default native CA trust can continue trusting
the native platform store after the application switches that same handle to
custom CA material for a later transfer. |
| The curl logic that works with SASL authentication could end up cleaning up
the GSASL context *twice* without clearing the pointer in between, making it
`free()` the same pointer twice. |
| An issue in curl’s QUIC UDP receive function allows a malicious HTTP/3 server
to trigger a remote denial of service against a curl or libcurl client.
Because the helper function discards zero-length UDP datagrams before counting
them toward the per-call packet budget, a connected QUIC peer can continuously
stream empty datagrams to indefinitely stall the client. |
| By default, curl automatically responds to WebSocket PING frames. Because curl
lacks an upper bound on memory allocation for unacknowledged frames, a
malicious server can exhaust all available memory by flooding curl with rapid,
sequential PING messages. |
| When reusing a libcurl handle for sequential transfers driven by
environment-variable proxy configuration, libcurl fails to clear the proxy
authentication state between requests. Specifically, if the initial transfer
authenticates against `proxyA` using Digest auth, a subsequent transfer routed
through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended
solely for `proxyA`. |
| Calling `curl_easy_pause()` within the event-based `CURLMOPT_SOCKETFUNCTION`
callback triggers a use-after-free vulnerability, where libcurl attempts to
store a flag using a dangling struct pointer immediately after that pointer's
memory has been freed. |
| A vulnerability exists where a new transfer that uses STARTTLS to upgrade the
connection might reuse an existing live connection even though the TLS
configuration mismatches so it should not. |
| libcurl had a flaw that when instructed to clear proxy authentication
credentials which made it not do so, leaving the old credentials around to get
used for subsequent transfers that should not know nor use them. |
| Successfully using libcurl to do a transfer over a specific HTTP proxy
(`proxyA`) with **Digest** authentication and then changing the proxy host to
a second one (`proxyB`) for a second transfer, reusing the same handle, makes
libcurl wrongly pass on the `Proxy-Authorization:` header field meant for
`proxyA`, to `proxyB`. |
| curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a
server, even if the new request uses different credentials for the HTTP proxy.
The proper behavior is to create or use a separate connection. |
| curl's code for managing SSH connections when SFTP was done using the wolfSSH
powered backend was flawed and missed host verification mechanisms.
This prevents curl from detecting MITM attackers and more. |
