GNU C Library (aka glibc or libc6) is vulnerable to a denial of service, caused by an assertion failure when processing invalid input sequences in the ISO-2022-JP-3 encoding in the iconv function. By sending specially-crafted input, a remote attacker could exploit this vulnerability to cause the application to crash.

An issue was discovered in OpenSSH 7.9. Due to missing character encoding in the progress display, a malicious server (or Man-in-The-Middle attacker) can employ crafted object names to manipulate the client output, e.g., by using ANSI control codes to hide additional files being transferred. This affects refreshprogressmeter() in progressmeter.c.

An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the scp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the scp client target directory. If recursive operation (-r) is performed, the server can manipulate subdirectories as well (for example, to overwrite the .ssh/authorizedkeys file).

In OpenSSH 7.9, scp.c in the scp client allows remote SSH servers to bypass intended access restrictions via the filename of . or an empty filename.

Upstream Patch:

https://github.com/openssh/openssh-portable/commit/6010c030 https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/scp.c.diff?r1=1.197&r2=1.198&f=h

A new attack was discovered against TLS that allows an attacker to recover a limited amount of plaintext from a TLS connection when RC4 encryption is used. The attacks arise from statistical flaws in the keystream generated by the RC4 algorithm which become apparent in TLS ciphertexts when the same plaintext is repeatedly encrypted at a fixed location across many TLS sessions.

Reference:

http://www.isg.rhul.ac.uk/tls/ http://blog.cryptographyengineering.com/2013/03/attack-of-week-rc4-is-kind-of-broken-in.html

Calls to EVPCipherUpdate, EVPEncryptUpdate and EVPDecryptUpdate may overflow the output length argument in some cases where the input length is close to the maximum permissable length for an integer on the platform. In such cases the return value from the function call will be 1 (indicating success), but the output length value will be negative. This could cause applications to behave incorrectly or crash. OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i). Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x).

A denial of service flaw was found in OpenSSL 0.9.8, 1.0.1, 1.0.2 through 1.0.2h, and 1.1.0 in the way the TLS/SSL protocol defined processing of ALERT packets during a connection handshake. A remote attacker could use this flaw to make a TLS/SSL server consume an excessive amount of CPU and fail to accept connections from other clients.

curl 7.21.0 to and including 7.73.0 is vulnerable to uncontrolled recursion due to a stack overflow issue in FTP wildcard match parsing.

A malicious server can use the PASV response to trick curl into connecting back to a given IP address and port, and this way potentially make curl extract information about services that are otherwise private and not disclosed, for example doing port scanning and service banner extractions. If curl operates on a URL provided by a user (which by all means is an unwise setup), a user can exploit that and pass in a URL to a malicious FTP server instance without needing any server breach to perform the attack.

Last updated 18 August 2025

curl 7.20.0 through 7.70.0 is vulnerable to improper restriction of names for files and other resources that can lead too overwriting a local file when the -J flag is used.

NTP is vulnerable to a denial of service, caused by an issue when relying on unauthenticated IPv4 time sources in ntpd. By predicting transmit timestamps for use in spoofed packets, a remote attacker could exploit this vulnerability to cause the daemon to crash or system time change.

It was found that libcurl might accidentally leak authentication data to third parties.

When asked to send custom headers in its HTTP requests, libcurl will send that set of headers first to the host in the initial URL but also, if asked to follow redirects and a 30X HTTP response code is returned, to the host mentioned in URL in the Location: response header value.

Sending the same set of headers to subsequest hosts is in particular a problem for applications that pass on custom Authorization: headers, as this header often contains privacy sensitive information or data that could allow others to impersonate the libcurl-using client's request.

This bug has existed since before curl 6.0.