Software update

Management

Software update systems allow for updates to be managed by users and software developers. In the 2017 Petya cyberpandemic, the financial software "MeDoc"'s update system is said to have been compromised to spread malware via its updates. On the Tor Blog, cybersecurity expert Mike Perry states that deterministic, distributed builds are likely the only way to defend against malware that attacks the software development and build processes to infect millions of machines in a single, officially signed, instantaneous update. Update managers also allow for security updates to be applied quickly and widely. Update managers of Linux such as Synaptic allow users to update all software installed on their machine. Applications like Synaptic use cryptographic checksums to verify source/local files before they are applied to ensure fidelity against malware.

Automatic updating has become more widespread over time. Some cite a cause of its prevalence to be due to Windows support in early 2000s. Service Pack 2 of Windows XP (available in 2004) enabled it by default.

Classification

Updates are classified many ways. Notable classifications in alphabetical order follow.

Hotfix

Malicious update

Some hacker may compromise legitimate software update channel and inject malicious code.

Patch

Patch release

Program temporary fix

{{Anchor|SECURITY}}Security patch

A security patch is a change to correct the weakness described by a vulnerability. The corrective action prevents successful exploitation and removes or mitigates a threat's capability to exploit a specific vulnerability. Patch management is a part of vulnerability management the cyclical practice of identifying, classifying, remediating, and mitigating vulnerabilities.

Security patches are the primary method of fixing security vulnerabilities in software. Currently Microsoft releases its security patches once a month ("patch Tuesday"), and other operating systems and software projects have security teams dedicated to releasing the most reliable software patches as soon after a vulnerability announcement as possible. Security patches are closely tied to responsible disclosure.

These security patches are critical to ensure that business process does not get affected. In 2017, companies were struck by a ransomware called WannaCry which encrypts files in certain versions of Microsoft Windows and demands a ransom via BitCoin. In response to this, Microsoft released a patch which stops the ransomware from running.

Service pack

Unofficial patch

Video game patch{{anchor|GAMING}}

A video game receives an update (often called a patch) to fix problems and to change features such as change game rules and algorithms. These updates may be prompted by the discovery of exploits in the multiplayer game experience that can be used to gain unfair advantages over other players. Extra features and gameplay tweaks can often be added. These kinds of updates are common in first-person shooters with multiplayer capability, and in MMORPGs, which are typically very complex with large amounts of content, almost always rely heavily on updates following the initial release, where updates sometimes add new content and abilities available to players. Because the balance and fairness for all players of an MMORPG can be severely corrupted within a short amount of time by an exploit, servers of an MMORPG are sometimes taken down with short notice to apply a critical fix.

Companies sometimes release games knowing that they have bugs. Computer Gaming Worlds Scorpia in 1994 denounced "companies—too numerous to mention—who release shoddy product knowing they can get by with patches and upgrades, and who make pay-testers of their customers".{{Cite magazine

Process

Software update processes vary dramatically. Some notable processes are described here.

Firmware update

Updating firmware (i.e. motherboard BIOS) can be challenging when it involves replacing the entire image on the hardware. As such, an error or interruption during the update process, such as loss of power, may render the hardware unusable.

An update, a binary image, is often installed via a supplier-provided program that overwrite the existing image with another. This program may safeguard against serious damage. For example, the update procedure could make and keep a backup of the firmware in case it determines that the primary copy is corrupt (i.e. via a checksum).

Limited release

In the cases of large updates or of significant changes, distributors often limit availability of updates to qualified developers as a beta test.

{{Anchor|HOT-PATCHING}}Hot patching

Hot patching, also known as live patching or dynamic software updating, is the application of patches without shutting down and restarting the system or the program concerned. This addresses problems related to unavailability of service provided by the system or the program. Method can be used to update Linux kernel without stopping the system. A patch that can be applied in this way is called a hot patch or a live patch. This is becoming a common practice in the mobile app space. Companies like Rollout.io use method swizzling to deliver hot patches to the iOS ecosystem. Another method for hot-patching iOS apps is JSPatch.

Cloud providers often use hot patching to avoid downtime for customers when updating underlying infrastructure.

Slipstreaming

Slipstreaming is the act of integrating updates into the installation files of their original app, so that the result allows a direct installation of the updated app.

The nature of slipstreaming means that it involves an initial outlay of time and work, but can save a lot of time (and, by extension, money) in the long term. This is especially significant for administrators that are tasked with managing a large number of computers, where typical practice for installing an operating system on each computer would be to use the original media and then update each computer after the installation was complete. This would take a lot more time than starting with a more up-to-date (slipstreamed) source, and needing to download and install the few updates not included in the slipstreamed source.

However, not all updates can be applied in this fashion and one disadvantage is that if it is discovered that a certain update is responsible for later problems, that update cannot be removed without using an original, non-slipstreamed installation source.

References

References

1. "Virus (cough, cough, Petya) goes postal at FedEx, shares halted".
2. (28 June 2017). "New Petya Distribution Vectors Bubbling to Surface". Threatpost.
3. "Deterministic Builds Part One: Cyberwar and Global Compromise {{!}} The Tor Blog".
4. (2008). "Introducing Ubuntu: Desktop Linux". Cengage Learning.
5. (2007). "HWM". SPH Magazines.
6. "How Malicious Software Updates Endanger Everyone". american civil liberties union.
7. "Oracle Magazine". Oracle.com.
8. "Live patching the Linux kernel".
9. (6 March 2020). "Linux Kernel Live Patching: What It is and Who Needs It".
10. "Hot or Not? The Benefits and Risks of iOS Remote Hot Patching « Threat Research Blog".
11. Perez, Sarah. (22 September 2015). "Rollout.io Puts Mobile Developers Back In Control Of Their Apps".
12. "bang590/JSPatch".
13. (2019-09-11). "Hot Patching SQL Server Engine in Azure SQL Database".
14. (14 July 2008). "Build an XP SP3 Recovery Disc". [[Ziff Davis]].
15. (7 May 2008). "Slipstreaming Windows XP with Service Pack 3 (SP3)". [[Penton (company).