Impact

The Keylime registrar does not enforce mutual TLS (mTLS) client certificate authentication since version 7.12.0. The registrar's TLS context is configured with ssl.CERTOPTIONAL instead of ssl.CERTREQUIRED, allowing any client to connect to protected API endpoints without presenting a valid client certificate.

Who is impacted: - All Keylime deployments running versions 7.12.0 through 7.13.0 - Environments where the registrar HTTPS port (default 8891) is network-accessible to untrusted clients

What an attacker can do: - List all registered agents (GET /v2/agents/) - enumerate the entire agent inventory - Retrieve agent details (GET /v2/agents/{uuid}) - obtain public TPM keys, certificates, and network locations (IP/port) of any agent - Delete any agent (DELETE /v2/agents/{uuid}) - remove agents from the registry, disrupting attestation services

Note: The exposed TPM data (EK, AK, certificates) consists of public keys and certificates. Private keys remain protected within TPM hardware. The HMAC secret used for challenge-response validation is stored in the database but is not exposed via the API.

Affected versions: >= 7.12.0, <= 7.13.0

Fixed versions: 7.12.2, >= 7.13.1

Patches

A patch for the affected released versions is available. It removes the line that override the configuration of ssl.verifymode, leaving the CERTREQUIRED value set by webutil.initmtls():

diff diff --git a/keylime/web/base/server.py b/keylime/web/base/server.py index 1d9a9c2..859b23a 100644 --- a/keylime/web/base/server.py +++ b/keylime/web/base/server.py @@ -2,7 +2,6 @@ import asyncio import multiprocessing from abc import ABC, abstractmethod from functools import wraps -from ssl import CERTOPTIONAL from typing import TYPECHECKING, Any, Callable, Optional

import tornado @@ -252,7 +251,6 @@ class Server(ABC): self.httpsport = config.getint(component, "tlsport", fallback=0) self.maxuploadsize = config.getint(component, "maxuploadsize", fallback=104857600) self.sslctx = webutil.initmtls(component) - self.sslctx.verifymode = CERTOPTIONAL

def get(self, pattern: str, controller: type["Controller"], action: str, allowinsecure: bool = False) -> None: """Creates a new route to handle incoming GET requests issued for paths which match the given

Users should upgrade to the patched version once it is released.

Workarounds

If upgrading is not immediately possible, apply one of the following mitigations:

1. Network isolation (Recommended)

Restrict access to the registrar HTTPS port (default 8891) using firewall rules to allow only trusted hosts (verifier, tenant):

Example using iptables iptables -A INPUT -p tcp --dport 8891 -s <verifierip> -j ACCEPT iptables -A INPUT -p tcp --dport 8891 -s <tenantip> -j ACCEPT iptables -A INPUT -p tcp --dport 8891 -j DROP

2. Reverse proxy with mTLS enforcement

Deploy a reverse proxy (nginx, HAProxy) in front of the registrar that enforces client certificate authentication:

Example nginx configuration server { listen 8891 ssl; sslcertificate /path/to/server.crt; sslcertificatekey /path/to/server.key; sslclientcertificate /path/to/ca.crt; sslverifyclient on; # Enforce client certificates

location / { proxypass https://localhost:8892; # Internal registrar port } }

apachemodphp. Multiple issues were addressed by updating to PHP version 7.3.11.

A crafted request uri-path can cause modproxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.

+5.9.2: + security: + - These two CVEs can be exploited by a user with read-only credentials: + - CVE-2022-24805 A buffer overflow in the handling of the INDEX of + NET-SNMP-VACM-MIB can cause an out-of-bounds memory access. + - CVE-2022-24809 A malformed OID in a GET-NEXT to the nsVacmAccessTable + can cause a NULL pointer dereference. + - These CVEs can be exploited by a user with read-write credentials: + - CVE-2022-24806 Improper Input Validation when SETing malformed + OIDs in master agent and subagent simultaneously + - CVE-2022-24807 A malformed OID in a SET request to + SNMP-VIEW-BASED-ACM-MIB::vacmAccessTable can cause an + out-of-bounds memory access. + - CVE-2022-24808 A malformed OID in a SET request to + NET-SNMP-AGENT-MIB::nsLogTable can cause a NULL pointer dereference + - CVE-2022-24810 A malformed OID in a SET to the nsVacmAccessTable + can cause a NULL pointer dereference. + - To avoid these flaws, use strong SNMPv3 credentials and do not share them. + If you must use SNMPv1 or SNMPv2c, use a complex community string + and enhance the protection by restricting access to a given IP address range. + - Thanks are due to Yu Zhang of VARAS@IIE and Nanyu Zhong of VARAS@IIE for + reporting the following CVEs that have been fixed in this release, and + to Arista Networks for providing fixes.

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A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBCTUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBCTUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.

Last updated 30 August 2024

A vulnerability was found in insights-client. This security issue occurs because of insecure file operations or unsafe handling of temporary files and directories that lead to local privilege escalation. Before the insights-client has been registered on the system by root, an unprivileged local user or attacker could create the /var/tmp/insights-client directory (owning the directory with read, write, and execute permissions) on the system. After the insights-client is registered by root, an attacker could then control the directory content that insights are using by putting malicious scripts into it and executing arbitrary code as root (trivially bypassing SELinux protections because insights processes are allowed to disable SELinux system-wide).

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A flaw was found in the Linux kernel's NVMe driver. This issue may allow an unauthenticated malicious actor to send a set of crafted TCP packages when using NVMe over TCP, leading the NVMe driver to a NULL pointer dereference in the NVMe driver and causing kernel panic and a denial of service.

A flaw was found in the Linux kernel's NVMe driver. This issue may allow an unauthenticated malicious actor to send a set of crafted TCP packages when using NVMe over TCP, leading the NVMe driver to a NULL pointer dereference in the NVMe driver, causing kernel panic and a denial of service.

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From https://github.com/net-snmp/net-snmp/blob/v5.9.2/CHANGES CVE-2022-24806 Improper Input Validation when SETing malformed OIDs in master agent and subagent simultaneously

https://github.com/net-snmp/net-snmp/blob/v5.9.2/CHANGES

CVE-2022-24808 A malformed OID in a SET request to NET-SNMP-AGENT-MIB::nsLogTable can cause a NULL pointer dereference

CVE-2022-24807 A malformed OID in a SET request to SNMP-VIEW-BASED-ACM-MIB::vacmAccessTable can cause an out-of-bounds memory access. https://github.com/net-snmp/net-snmp/blob/v5.9.2/CHANGES

https://github.com/net-snmp/net-snmp/blob/v5.9.2/CHANGES CVE-2022-24809 A malformed OID in a GET-NEXT to the nsVacmAccessTable can cause a NULL pointer dereference.

A symlink traversal vulnerability in the containers/storage library can cause Podman, Buildah, and CRI-O to hang and potentially be DoSed via OOM kill when running a malicious image using an automatically assigned user namespace (--userns=auto in Podman and Buildah). The containers/storage library will read /etc/passwd inside the container, but does not properly validate if that file is a symlink, which can be used to cause the library to read an arbitrary file on the host. This file is only read, and if it does not properly parse as a copy of /etc/passwd it will cause an error (there is a small risk of information disclosure via the error message here as elements of the file that failed to parse can be included, but this is only as the user running Podman/Buildah/CRI-O so it wouldn't be a file they did not already have access to). The report here discovered that you can symlink /etc/passwd in the container to a FIFO on the host, causing a hang as the file cannot be completely read (or an OOM condition if the FIFO is continuously written to, which was then ready by Podman). This hang could occur in a critical section in the c/storage library, blocking other processes from creating containers, but could be easily solved via a SIGKILL of the affected process. The ability to potentially crash the CRI-O service via OOM kill could be more relevant, though the attacker would have to know the path of a FIFO that is regularly being written to on the host in order to do this.

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