Excessive time spent in DH check / generation with large Q parameter value

Issue summary: Processing some specially crafted ASN.1 object identifiers or data containing them may be very slow.

Impact summary: Applications that use OBJobj2txt() directly, or use any of the OpenSSL subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS with no message size limit may experience notable to very long delays when processing those messages, which may lead to a Denial of Service.

A double-free vulnerability was found in OpenSSL's PEMreadbioex function. The function PEMreadbioex() reads a PEM file from a BIO and parses and decodes the "name" (for example, "CERTIFICATE"), any header data, and the payload data. If the function succeeds, then the "nameout," "header," and "data" arguments are populated with pointers to buffers containing the relevant decoded data. The caller is responsible for freeing those buffers. Constructing a PEM file that results in 0 bytes of payload data is possible. In this case, PEMreadbioex() will return a failure code but will populate the header argument with a pointer to a freed buffer. A double-free will occur if the caller also frees this buffer. This will most likely lead to a crash. This could be exploited by an attacker who can supply malicious PEM files for parsing to achieve a denial of service attack.

A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, only applications that directly call the SSLfreebuffers function are affected by this issue. Applications that do not call this function are not vulnerable. Our investigations indicate that this function is rarely used by applications.

The SSLfreebuffers function is used to free the internal OpenSSL buffer used when processing an incoming record from the network. The call is only expected to succeed if the buffer is not currently in use. However, two scenarios have been identified where the buffer is freed even when still in use.

The first scenario occurs where a record header has been received from the network and processed by OpenSSL, but the full record body has not yet arrived. In this case calling SSLfreebuffers will succeed even though a record has only been partially processed and the buffer is still in use.

The second scenario occurs where a full record containing application data has been received and processed by OpenSSL but the application has only read part of this data. Again a call to SSLfreebuffers will succeed even though the buffer is still in use.

While these scenarios could occur accidentally during normal operation a malicious attacker could attempt to engineer a stituation where this occurs. We are not aware of this issue being actively exploited.

The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.

OpenSSL 1.0.2 is also not affected by this issue.

OpenSSL 3.3, 3.2, 3.1, 3.0 and 1.1.1 are vulnerable to this issue.

OpenSSL 3.3 users should upgrade to OpenSSL 3.3.1 once it is released.

OpenSSL 3.2 users should upgrade to OpenSSL 3.2.2 once it is released.

OpenSSL 3.1 users should upgrade to OpenSSL 3.1.6 once it is released.

OpenSSL 3.0 users should upgrade to OpenSSL 3.0.14 once it is released.

OpenSSL 1.1.1 users should upgrade to OpenSSL 1.1.1y once it is released (premium support customers only).

Due to the low severity of this issue we are not issuing new releases of OpenSSL at this time. The fix will be included in the next releases when they become available. The fix is also available in commit e5093133c3 (for 3.3), commit c88c3de510 (for 3.2), commit 704f725b96 (for 3.1) and commit b3f0eb0a29 (for 3.0) in the OpenSSL git repository. It is available to premium support customers in commit f7a045f314 (for 1.1.1).

This issue was reported on 10th April 2024 by William Ahern (Akamai). The fix was developed by Matt Caswell and Watson Ladd (Akamai).

A flaw in the Linux Kernel found. An out-of-bounds write vulnerability in the Linux kernel's net/sched: schqfq component can be exploited to achieve local privilege escalation. The qfqchangeagg() function in net/sched/schqfq.c allows an out-of-bounds write because lmax is updated according to packet sizes without bounds checks.

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3e337087c3b5805fe0b8a46ba622a962880b5d64

A flaw in the Linux Kernel found. A use-after-free vulnerability in the Linux kernel's net/sched: clsfw component can be exploited to achieve local privilege escalation. If tcfchangeindev() fails, fwsetparms() will immediately return an error after incrementing or decrementing the reference counter in tcfbindfilter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability.

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=0323bce598eea038714f941ce2b22541c46d488f

A use-after-free flaw was found in route4change in the net/sched/clsroute.c filter implementation in the Linux kernel. This flaw allows a local user to crash the system and possibly lead to a local privilege escalation problem.

An issue was discovered in Python before 3.8.18 3.9.x before 3.9.18 3.10.x before 3.10.13 and 3.11.x before 3.11.5. It primarily affects servers (such as HTTP servers) that use TLS client authentication. If a TLS server-side socket is created receives data into the socket buffer and then is closed quickly there is a brief window where the SSLSocket instance will detect the socket as "not connected" and won't initiate a handshake but buffered data will still be readable from the socket buffer. This data will not be authenticated if the server-side TLS peer is expecting client certificate authentication and is indistinguishable from valid TLS stream data. Data is limited in size to the amount that will fit in the buffer. (The TLS connection cannot directly be used for data exfiltration because the vulnerable code path requires that the connection be closed on initialization of the SSLSocket.)

A flaw has been discovered in GnuTLS where an application crash can be induced when attempting to verify a specially crafted .pem bundle using the "certtool --verify-chain" command.

A flaw was found in GnuTLS. The Minerva attack is a cryptographic vulnerability that exploits deterministic behavior in systems like GnuTLS, leading to side-channel leaks. In specific scenarios, such as when using the GNUTLSPRIVKEYFLAGREPRODUCIBLE flag, it can result in a noticeable step in nonce size from 513 to 512 bits, exposing a potential timing side-channel.

A vulnerability was found that the response times to malformed ciphertexts in RSA-PSK ClientKeyExchange differ from response times of ciphertexts with correct PKCS#1 v1.5 padding.

A vulnerability was found in GnuTLS. The response times to malformed ciphertexts in RSA-PSK ClientKeyExchange differ from the response times of ciphertexts with correct PKCS#1 v1.5 padding. This issue may allow a remote attacker to perform a timing side-channel attack in the RSA-PSK key exchange, potentially leading to the leakage of sensitive data. CVE-2024-0553 is designated as an incomplete resolution for CVE-2023-5981.

A flaw was found in the Apache Portable Runtime Utility (APR-util) library. This issue may allow a malicious attacker to cause an out-of-bounds write due to an integer overflow when encoding/decoding a very long string using the base64 family of functions.

It was discovered that the numerical library used in NSS for RSA cryptography leaks information whether high order bits of the RSA decryption result are zero. This information can be used to mount a Bleichenbacher or Manger like attack against all RSA decryption operations. As the leak happens before any padding operations, it affects all padding modes: PKCS#1 v1.5, OAEP, and RSASVP. Both API level calls and TLS server operation are affected.

References: https://people.redhat.com/~hkario/marvin/

An unspecified vulnerability in Java SE related to the Libraries component could allow an unauthenticated attacker to cause no confidentiality impact, low integrity impact, and no availability impact.

Apache HTTP Server is vulnerable to server-side request forgery, caused by a flaw in the modrewrite. By sending a specially crafted request, an attacker could exploit this vulnerability to cause unsafe RewriteRules to unexpectedly setup URL's to be handled by modproxy.

Apache HTTP Server contains an improper escaping of output vulnerability in modrewrite that allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any URL, resulting in code execution or source code disclosure.

Apache. This is a vulnerability in open source code and Apple Software among the affected projects. The CVE-ID was assigned by a third party. Learn more about the issue and CVE-ID at cve.org.

CVE-2024-38474 Substitution encoding issue in modrewrite in Apache HTTP Server 2.4.59 and earlier allows attacker to execute scripts in directories permitted by the configuration but not directly reachable by any URL or source disclosure of scripts meant to only to be executed as CGI. Users are recommended to upgrade to version 2.4.60, which fixes this issue. Some RewriteRules that capture and substitute unsafely will now fail unless rewrite flag "UnsafeAllow3F" is specified. CVE-2024-38475 Improper escaping of output in modrewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to map URLs to filesystem locations that are permitted to be served by the server but are not intentionally/directly reachable by any URL, resulting in code execution or source code disclosure. Substitutions in server context that use a backreferences or variables as the first segment of the substitution are affected. Some unsafe RewiteRules will be broken by this change and the rewrite flag "UnsafePrefixStat" can be used to opt back in once ensuring the substitution is appropriately constrained.

Apache HTTP Server could allow a remote attacker to bypass security restrictions, caused by an encoding flaw in modproxy. By sending specially crafted requests with incorrect encoding an attacker could exploit this vulnerability to bypass authentication validation.

glibc is vulnerable to a denial of service, caused by a memory allocation failure when the Name Service Cache Daemon's (nscd) netgroup cache uses the xmalloc or xrealloc functions. A local attacker could exploit this vulnerability to terminate the daemon.

Last updated 11 July 2025

Jinja is an extensible templating engine. The xmlattr filter in affected versions of Jinja accepts keys containing non-attribute characters. XML/HTML attributes cannot contain spaces, /, >, or =, as each would then be interpreted as starting a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. The fix for CVE-2024-22195 only addressed spaces but not other characters. Accepting keys as user input is now explicitly considered an unintended use case of the xmlattr filter, and code that does so without otherwise validating the input should be flagged as insecure, regardless of Jinja version. Accepting values as user input continues to be safe. This vulnerability is fixed in 3.1.4.

c-ares is a C library for asynchronous DNS requests. aresreadline() is used to parse local configuration files such as /etc/resolv.conf, /etc/nsswitch.conf, the HOSTALIASES file, and if using a c-ares version prior to 1.27.0, the /etc/hosts file. If any of these configuration files has an embedded NULL character as the first character in a new line, it can lead to attempting to read memory prior to the start of the given buffer which may result in a crash. This issue is fixed in c-ares 1.27.0. No known workarounds exist.

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja xmlattr filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

OpenSSH through 10.0, when common types of DRAM are used, might allow row hammer attacks (for authentication bypass) because the integer value of authenticated in mmanswerauthpassword does not resist flips of a single bit. NOTE: this is applicable to a certain threat model of attacker-victim co-location in which the attacker has user privileges. NOTE: this is disputed by the Supplier, who states "we do not consider it to be the application's responsibility to defend against platform architectural weaknesses."

Accessibility. A privacy issue was addressed with improved private data redaction for log entries.

DISPUTED Xmlsoft Libxml2 v2.11.0 was discovered to contain an out-of-bounds read via the xmlSAX2StartElement() function at /libxml2/SAX2.c. This vulnerability allows attackers to cause a Denial of Service (DoS) via supplying a crafted XML file. NOTE: the vendor's position is that the product does not support the legacy SAX1 interface with custom callbacks; there is a crash even without crafted input.

In libxml2 before 2.10.4, parsing of certain invalid XSD schemas can lead to a NULL pointer dereference and subsequently a segfault. This occurs in xmlSchemaFixupComplexType in xmlschemas.c.

ext/fts3/fts3.c in SQLite before 3.32.0 has a use-after-free in fts3EvalNextRow, related to the snippet feature.