A UNIX Symbolic Link (Symlink) Following vulnerability in openSUSE Tumbleweed suricata package allows the suricata user to escalate to root.

This issue affects openSUSE Tumbleweed: from ? before 8.0.5-2.1; openSUSE Tumbleweed: from ? before 8.0.5-2.1.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. A PCRE rule can be written that leads to an infinite loop when negated PCRE is used. Packet processing thread becomes stuck in infinite loop limiting visibility and availability in inline mode. This vulnerability is fixed in 7.0.9.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. The bytes setting in the decodebase64 keyword is not properly limited. Due to this, signatures using the keyword and setting can cause large memory allocations of up to 4 GiB per thread. This vulnerability is fixed in 7.0.9.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Datasets declared in rules have an option to specify the hashsize to use. This size setting isn't properly limited, so the hash table allocation can be large. Untrusted rules can lead to large memory allocations, potentially leading to denial of service due to resource starvation. This vulnerability is fixed in 7.0.9.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. The AFPACKET defrag option is enabled by default and allows AFPACKET to re-assemble fragmented packets before reaching Suricata. However the default packet size in Suricata is based on the network interface MTU which leads to Suricata seeing truncated packets. Upgrade to Suricata 7.0.9, which uses better defaults and adds warnings for user configurations that may lead to issues.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.8, TCP streams with TCP urgent data (out of band data) can lead to Suricata analyzing data differently than the applications at the TCP endpoints, leading to possible evasions. Suricata 7.0.8 includes options to allow users to configure how to handle TCP urgent data. In IPS mode, you can use a rule such as drop tcp any any -> any any (sid:1; tcp.flags:U;) to drop all the packets with urgent flag set.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to version 7.0.8, DNS resource name compression can lead to small DNS messages containing very large hostnames which can be costly to decode, and lead to very large DNS log records. While there are limits in place, they were too generous. The issue has been addressed in Suricata 7.0.8.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.8, a specially crafted TCP stream can lead to a very large buffer overflow while being zero-filled during initialization with memset due to an unsigned integer underflow. The issue has been addressed in Suricata 7.0.8.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.8, a large BPF filter file provided to Suricata at startup can lead to a buffer overflow at Suricata startup. The issue has been addressed in Suricata 7.0.8.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.8, a large input buffer to the tolowercase, touppercase, stripwhitespace, compresswhitespace, dotprefix, headerlowercase, strippseudoheaders, urldecode, or xor transform can lead to a stack overflow causing Suricata to crash. The issue has been addressed in Suricata 7.0.8.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to version 7.0.7, missing initialization of the random seed for "thash" leads to byte-range tracking having predictable hash table behavior. This can lead to an attacker forcing lots of data into a single hash bucket, leading to severe performance degradation. This issue has been addressed in 7.0.7.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to version 7.0.7, missing initialization of the random seed for "thash" leads to datasets having predictable hash table behavior. This can lead to dataset file loading to use excessive time to load, as well as runtime performance issues during traffic handling. This issue has been addressed in 7.0.7. As a workaround, avoid loading datasets from untrusted sources. Avoid dataset rules that track traffic in rules.

Here is the fourth Landlock newsletter!

Official website: https://landlock.io Previews newsletter: https://lore.kernel.org/landlock/d4ed5733-d07b-5548-2534-a63e22906778 () digikod net

Articles and conferences ------------------------

We wrote a detailed article about Landlock explaining the underlying concepts, the implementation, and the community: https://landlock.io/talks/2024-06-06landlock-article.pdf This was written for the SSTIC conference: https://www.sstic.org/2024/presentation/landlock-design/

I did a workshop at the Pass the Salt conference to explain how to mitigate security vulnerabilities with Landlock (demonstrated with ImageMagick): https://cfp.pass-the-salt.org/pts2024/talk/8FVYDF/ Related materials are freely available to do it at home: https://github.com/landlock-lsm/workshop-imagemagick

Arto Niemi published a "Survey of Real-World Process Sandboxing" at the Conference of Open Innovations Association (FRUCT): https://fruct.org/publications/volume-35/fruct35/files/Niem.pdf Their conclusion: "[...] we found Landlock and minijail [which uses Landlock] to be relatively convenient from a developer perspective. In general, process self-containment and process-wrapping seems to be an order of magnitude easier to configure than MAC policies."

Researchers from University of Bergamo gave a talk at ASIA CCS conference about Cage4Deno: A Fine-Grained Sandbox for Deno Subprocesses (leveraging Landlock) https://cs.unibg.it/seclab-papers/2023/ASIACCS/paper/cage4deno.pdf They also gave a talk at the RAID conference about NatiSand: Native Code Sandboxing for JavaScript Runtimes (leveraging Landlock) https://cs.unibg.it/seclab-papers/2023/RAID/natisand.pdf

Eric Leblond gave a talk (in French) at the SSTIC conference about sandboxing with Landlock to mitigate real world security issues: https://www.sstic.org/2023/presentation/attaquesupplychainsuricata/

Günther Noack will give a talk at LSS Europe about Landlock and the new IOCTL support: https://sched.co/1ebVW

I'll give a talk at OSS Europe to better explain sandboxing with Landlock: https://sched.co/1ej3a

The XZ backdoor ---------------

XZ Utils is a widely used compression tool and library. The main maintainer implemented sandboxing with Landlock, and released a new version 5.6.0 with this feature. In March 2024, a backdoor was found and reported. It was introduced in February by a new maintainer who earned this trust after more than two years of effort.

Among the malicious changes, the attacker disabled Landlock's support for XZ Utils and released a new version 5.6.1: https://research.swtch.com/xz-timeline The sabotaged configuration check has since been fixed with version 5.6.2, but this effort to stealthily disable sandboxing is a clear sign that Landlock disturbs attackers: https://github.com/tukaani-project/xz/commit/f9cf4c05edd1

Merged kernel features ----------------------

Linux 6.7 (Landlock ABI 4) supports initial network access control with the LANDLOCKACCESSNETBINDTCP and LANDLOCKACCESSNETCONNECTTCP rights thanks to Konstantin Meskhidze. We can now control inbound and outbound TCP connections according to the source or the destination port. This led to kernel code refactoring which opens the way to more network protocol support. See user space documentation: https://docs.kernel.org/userspace-api/landlock.html#network-flags

Linux 6.10 (Landlock ABI 5) supports IOCTL control with the new LANDLOCKACCESSFSIOCTLDEV right thanks to Günther Noack. This restriction only applies to IOCTL commands implemented by device drivers (i.e. block or character devices). As other file system access rights, this can be used to only allow such IOCTL commands on a specified set of file hierarchies per sandbox. See user space documentation: https://docs.kernel.org/userspace-api/landlock.html#filesystem-flags

We also added a slight change in all supported kernels to inform system administrators (with kernel logs) how they can configure the system to support Landlock, if a process tried to sandbox itself on a kernel where Landlock is disabled. New documentation will help enable Landlock on systems when it is not already the case: https://docs.kernel.org/userspace-api/landlock.html#kernel-support

Since Linux 6.3, we improved documentation and kselftests (user space testing), and added support for KUnit (kernel testing). Part of this work lead us to support the UML architecture to easily run application tests in a CI against different kernel versions. With this support we can make sure that backward compatibility works fine for the tested applications. I encourage to take a look at landlock-test-tools and the GitHub CI configuration for the Rust library: https://github.com/landlock-lsm/landlock-test-tools https://github.com/landlock-lsm/rust-landlock/blob/main/.github/workflows/rust.yml#L166-L179

Roadmap and ongoing development -------------------------------

We created GitHub issues to track ongoing and future work: https://github.com/landlock-lsm/linux/issues https://github.com/orgs/landlock-lsm/projects/1

Feel free to reach out if you want to contribute! https://github.com/landlock-lsm/linux/contribute

We also plan to improve the website with extended documentation and examples.

Kernel development highlights -----------------------------

Günther Noack is now an official reviewer of Landlock! https://git.kernel.org/torvalds/c/5bf9e57e634b After the IOCTL feature, he is now working on improving the documentation, including man pages.

Mikhail Ivanov is working on socket type control. This is an important feature that will make it possible to create sandboxes without any network access, except for an explicit list of allowed protocols. This will nicely complement the TCP port control (and future ones for other protocols): https://github.com/landlock-lsm/linux/issues/6 He is also working on controlling TCP listen calls: https://github.com/landlock-lsm/linux/issues/15

Tahera Fahimi was selected as an Outreachy intern to work on IPC restrictions (e.g. abstract unix socket, signals) to better isolate a Landlock domain: https://github.com/landlock-lsm/linux/issues/7 https://github.com/landlock-lsm/linux/issues/8

I'm working on bringing audit support to Landlock: https://github.com/landlock-lsm/linux/issues/3

Landlock libraries ------------------

As explained by Günther Noack, the Go library now supports TCP and IOCTL restrictions: https://blog.gnoack.org/post/landlock-v4/ https://blog.gnoack.org/post/landlock-ioctl/

A new version of the Rust crate was released, with support for TCP control and some miscellaneous improvements: https://github.com/landlock-lsm/rust-landlock/releases/tag/v0.4.0

Please update your dependencies and use the latest Landlock ABI version for improved sandboxing.

We are also working on a new minimal C library: https://github.com/landlock-lsm/linux/issues/38

New Landlock user space supports --------------------------------

Firejail 0.9.74 (sandboxer) will be able to use landlock: https://github.com/netblue30/firejail/pull/6078

setpriv 2.40 (sandboxer): https://github.com/util-linux/util-linux/pull/2628

extrasafe 0.4.0 (sandbox library): https://github.com/boustrophedon/extrasafe/pull/28

bevymodlockdown (sandbox library): https://github.com/FrTerstappen/bevymodlockdown

Cloud Hypervisor (VM monitor) will be sandboxed with Landlock: https://github.com/cloud-hypervisor/cloud-hypervisor/pull/6214

Ukuleleweb (wiki server): https://github.com/gnoack/ukuleleweb/commit/0ecdd54b36fa

websrv 3.2.0 (web server): https://github.com/ngergs/websrv/commit/40fa2d7d2bbb

egress-eddie 0.5.0 (network filtering): https://github.com/capnspacehook/egress-eddie/releases/tag/v0.5.0

Suricata 7.0.0 (network security monitoring engine): https://docs.suricata.io/en/latest/configuration/landlock.html

sslh 2.1.0 (protocol multiplexer): https://lore.kernel.org/landlock/Zfq6f30spnYCx9Y () rutschle net/ https://github.com/yrutschle/sslh/releases/tag/v2.1.0

wireproxy 1.0.8 (Wireguard client): https://github.com/pufferffish/wireproxy/pull/108

Emilua 0.5.0 (Lua runtime): https://lore.kernel.org/landlock/CAK9RveLxro4zUG4jfFB=UNgcv5gdc8JuzNhMt=YbNhH=35ADzg () mail gmail com/ https://docs.emilua.org/api/0.5/changelog.html

Polkadot (blockchain SDK): https://github.com/paritytech/polkadot/pull/7303

XZ Utils 5.6.2 (archive manager): https://github.com/tukaani-project/xz/commit/374868d81d47

Zathura (document viewer) will be sandboxed with Landlock: https://github.com/pwmt/zathura/pull/575

Pacman 7.0.0 (Arch Linux's package manager): https://gitlab.archlinux.org/pacman/pacman/-/mergerequests/167

Thanks to all contributors!

Regards, Mickaël

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. A memory allocation failure due to http.memcap being reached leads to a NULL-ptr reference leading to a crash. Upgrade to 7.0.6.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Suricata can run out of memory when parsing crafted HTTP/2 traffic. Upgrade to 6.0.20 or 7.0.6.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Crafted modbus traffic can lead to unlimited resource accumulation within a flow. Upgrade to 7.0.6. Set a limited stream.reassembly.depth to reduce the issue.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.5 and 6.0.19, various problems in handling of fragmentation anomalies can lead to mis-detection of rules and policy. This vulnerability is fixed in 7.0.5 or 6.0.19.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to 7.0.5 and 6.0.19, specially crafted traffic or datasets can cause a limited buffer overflow. This vulnerability is fixed in 7.0.5 and 6.0.19. Workarounds include not use rules with base64decode keyword with bytes option with value 1, 2 or 5 and for 7.0.x, setting app-layer.protocols.smtp.mime.body-md5 to false.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine developed by the OISF and the Suricata community. When parsing an overly long SSH banner, Suricata can use excessive CPU resources, as well as cause excessive logging volume in alert records. This issue has been patched in versions 6.0.17 and 7.0.4.

Directory Traversal vulnerability found in Pfsense v.2.1.3 and Pfsense Suricata v.1.4.6 pkg v.1.0.1 allows a remote attacker to obtain sensitive information via the file parameter to suricata/suricatalogsbrowser.php.

An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.

Suricata before 5.0.8 and 6.x before 6.0.4 allows TCP evasion via a client with a crafted TCP/IP stack that can send a certain sequence of segments.

Various security, performance, accuracy and stability issues have been fixed, including a critical evasion assigned CVE-2021-35063.

Reference: https://forum.suricata.io/t/suricata-6-0-3-and-5-0-7-released/1489

An issue was discovered in Suricata 5.0.0. It was possible to bypass/evade any tcp based signature by faking a closed TCP session using an evil server. After the TCP SYN packet, it is possible to inject a RST ACK and a FIN ACK packet with a bad TCP Timestamp option. The client will ignore the RST ACK and the FIN ACK packets because of the bad TCP Timestamp option. Both linux and windows client are ignoring the injected packets.

An issue was discovered in Suricata 5.0.0. It is possible to bypass/evade any tcp based signature by overlapping a TCP segment with a fake FIN packet. The fake FIN packet is injected just before the PUSH ACK packet we want to bypass. The PUSH ACK packet (containing the data) will be ignored by Suricata because it overlaps the FIN packet (the sequence and ack number are identical in the two packets). The client will ignore the fake FIN packet because the ACK flag is not set. Both linux and windows clients are ignoring the injected packet.

In OISF LibHTP before 0.5.31, as used in Suricata 4.1.4 and other products, an HTTP protocol parsing error causes the httpheader signature to not alert on a response with a single \r\n ending.

An issue was discovered in Suricata 4.1.4. By sending multiple fragmented IPv4 packets, the function Defrag4Reassemble in defrag.c tries to access a memory region that is not allocated, because of a lack of headerlen checking.

An issue was discovered in Suricata 4.1.4. By sending multiple IPv4 packets that have invalid IPv4Options, the function IPV4OptValidateTimestamp in decode-ipv4.c tries to access a memory region that is not allocated. There is a check for o->len < 5 (corresponding to 2 bytes of header and 3 bytes of data). Then, "flag = (o->data + 3)" places one beyond the 3 bytes, because the code should have been "flag = (o->data + 1)" instead.

An issue was discovered in app-layer-ssl.c in Suricata 4.1.4. Upon receiving a corrupted SSLv3 (TLS 1.2) packet, the parser function TLSDecodeHSHelloExtensions tries to access a memory region that is not allocated, because the expected length of HSHelloExtensions does not match the real length of the HSHelloExtensions part of the packet.

An issue was discovered in Suricata 4.1.3. The code mishandles the case of sending a network packet with the right type, such that the function DecodeEthernet in decode-ethernet.c is executed a second time. At this point, the algorithm cuts the first part of the packet and doesn't determine the current length. Specifically, if the packet is exactly 28 long, in the first iteration it subtracts 14 bytes. Then, it is working with a packet length of 14. At this point, the case distinction says it is a valid packet. After that it casts the packet, but this packet has no type, and the program crashes at the type case distinction.