6 ms·

On my machine, the Steam folder is writable by the Users group. I didn't modify anything so I assume Steam set it that way.

by dtech 7y ago

yrro 7y ago
Of course, how else is a user running Steam supposed to update it? Headdesk
- batat 7y ago
  Through Steam service running as NT AUTHORITY\SYSTEM? Like "Mozilla Maintenance Service" for Firefox.
  - yrro 7y ago
    That would require Valve's developers have a clue about basic security...
    - shawnz 7y ago
      It's ironic, because Gabe Newell himself started at Microsoft. Now he's created a company in which apparently none of his employees understand the security model of Microsoft products.
AnIdiotOnTheNet 7y ago
If true, then I stand corrected. However, I'll point out that one hardly needs administrator access to, say, encrypt your documents and install a crypto miner. The whole idea that gaining administrator privileges through local escalation on a personal desktop is A Big Deal(TM) is silly.
- r1ch 7y ago
  Microsoft considers this kind of escalation a security issue and will issue patches if this is found in Windows components. If Steam is installed on a corporate network PC (game development, QA services, esports teams, etc?), regular users being able to elevate to machine admin is a big deal.
  - AnIdiotOnTheNet 7y ago
    > Microsoft considers this kind of escalation a security issue and will issue patches if this is found in Windows components. Makes sense, because Windows is also used for servers. The Steam client is not. > If Steam is installed on a corporate network PC (game development, QA services, esports teams, etc?), regular users being able to elevate to machine admin is a big deal. No it isn't. This is effectively the same as being installed on some home PC. Being local admin on the workstation doesn't really give you any more ability to do damage than just a regular user account. A non-administrative process still has access to all the user's stuff, and all the network resources that user account has access to. Local admin doesn't really give you anything new.
    - deleted 7y ago
      [deleted]
      - deleted 7y ago
        [deleted]
    - lurker458 7y ago
      local admin on windows is similar to having sudo rights on linux. It can be used to access personal files and running sessions of other users on the same machine, to install malware that will affect other users, to change drivers, to block AV or GPO policies from being applied to protect them, etc.
      - delfinom 7y ago
        Local admin just makes the life of IT guys more difficult. It's why we don't give it out to your typical "worker drone" employees because they'll manage to install many flash players that want to admin escalate....
        AnIdiotOnTheNet 7y ago
        I've found the opposite, that for the most part people just want to be able to do their job and sometimes they need administrator rights for that, and it is incredibly annoying and frictionful if they need to contact IT every time. Since workstations are almost always 1:1, we don't consider whatever advantages local admin might provide an attacker to be worth the extra friction caused by disallowing it.
- 0xDEFC0DE 7y ago
  >The whole idea that gaining administrator privileges through local escalation on a personal desktop is A Big Deal(TM) is silly. I’ve seen steam on work computers. This isn’t limited to home desktop users by any stretch. People install steam because they don’t know it puts their work computers at risk. You could argue that they shouldn’t have games on a work PC (some companies are a bit more lax and even play together) and an easy way to convince them to not do that is if you point out that Steam makes your system less secure by design.
  - AnIdiotOnTheNet 7y ago
    > People install steam because they don’t know it puts their work computers at risk. Tell me, what precisely does having administrator privileges on a workstation provide that having the user account's privileges does not? With the user account you still have access to the user's files (and they are almost certainly the only user of that workstation) and all network resources they have access to.
    - 0xDEFC0DE 7y ago
      Install persistence, stealth like clearing logs, gather more information from AD, run code that wouldn’t otherwise be possible. But no let’s just forget all of the reasons we use group policy and principles of least privileges. Imagine if your initial foothold is user with Steam installed. You just got SYSTEM for free.
      - AnIdiotOnTheNet 7y ago
        > gather more information from AD What good is the computer account for this when you already have the user account? > But no let’s just forget all of the reasons we use group policy and principles of least privileges. By that rationale, computer accounts should have far fewer privileges than the actual user account anyway, so again having local admin isn't worth much. > run code that wouldn’t otherwise be possible Namely? > Imagine if your initial foothold is user with Steam installed. You just got SYSTEM for free. And I'm struggling to see how that adds much to my problem of someone having a foothold on a user workstation already. And that's ignoring the circumstances of Steam being installed on the workstation in the first place AND the user having installed some untrustworthy game with it in the window since the game's appearance on Steam and its detection and removal. Which is also not to mention that this means the user has the ability to install software and is therefore infinitely more likely to just download some malicious installer from the nefarious portions of the internet that they can access with a web browser.
- jerf 7y ago
  As the degree of privilege you get on a system goes up, your ability to persist attacks increases. In the limit you end up with cases where the malware is running as a hypervisor, rendering Windows actually entirely incapable of seeing it or dealing with it. I seem to recall some countermeasures have been added but I don't recall all the details or know what the current status of that is, but I'm fairly sure that has has happened in the wild, not just a theoretical attack. So even if someone gets exec on your user files, you'd still prefer them to be limited to your user and not running at higher priv levels. Even if 90% of the damage is done with access to your personal files, it still adds more damage with higher privs. Plus this means user-level countermeasures like "run steam as a separate user" are useful; with escalation, that's not an effective defense. Also, if you've got multiple users on the computer, an attack that can't escalate privileges might ruin your day, but an attack that can escalate privileges might ruin your day and your spouse's day and anyone else in your family's day, so even in terms of "personal files" on a modern Windows system you can still be looking at more damage from an escalating attack.
  - AnIdiotOnTheNet 7y ago
    Of the people trying to say this is a big deal in any way, I must say that so far you are the only one to make any reasonable points. > So even if someone gets exec on your user files, you'd still prefer them to be limited to your user and not running at higher priv levels. Even if 90% of the damage is done with access to your personal files, it still adds more damage with higher privs. This is debatable, since whatever other damage they could do is something I'm not likely to care very much about compared to all my work, the whole reason I have a computer in the first place, being held for ransom or otherwise lost to me. > Plus this means user-level countermeasures like "run steam as a separate user" are useful; with escalation, that's not an effective defense. I suppose this is true, however I don't think any competent authority will tell you that simply running a program you don't trust as another user should ever be relied upon as a sandboxing mechanism anyway. > Also, if you've got multiple users on the computer, an attack that can't escalate privileges might ruin your day, but an attack that can escalate privileges might ruin your day and your spouse's day and anyone else in your family's day, so even in terms of "personal files" on a modern Windows system you can still be looking at more damage from an escalating attack. That's a fair point.
- la_barba 7y ago
  I think we all realize that you don't need admin privileges to do harm. Simply having any kind of access is sufficient. But if you want to install a system wide keylogger to get access to bank/finance logins, for e.g.. admin privs help.
  - AnIdiotOnTheNet 7y ago
    Eh, not as much as you'd think. I've written keyloggers. In the XP days running a keylogger under local admin ensured you'd get everything, but that stopped working around the time of Vista. So now what you have to do is launch your keylogger process in the user session context anyway. Admin access would just get you the ability to do it to more than just the initially compromised account, but in my experience workstations are 1:1 so that doesn't really get you anything.
    - la_barba 7y ago
      Hmm, don't you need SeDebugPrivilege to access the process space of another process launched by the same user account?

On my machine, the Steam folder is writable by the Users group. I didn't modify anything so I assume Steam set it that way.

by dtech 7y ago

On my machine, the Steam folder is writable by the Users group. I didn't modify anything so I assume Steam set it that way.

yrro 7y ago

Of course, how else is a user running Steam supposed to update it? Headdesk

batat 7y ago
Through Steam service running as NT AUTHORITY\SYSTEM? Like "Mozilla Maintenance Service" for Firefox.
- yrro 7y ago
  That would require Valve's developers have a clue about basic security...
  - shawnz 7y ago
    It's ironic, because Gabe Newell himself started at Microsoft. Now he's created a company in which apparently none of his employees understand the security model of Microsoft products.

AnIdiotOnTheNet 7y ago

If true, then I stand corrected. However, I'll point out that one hardly needs administrator access to, say, encrypt your documents and install a crypto miner. The whole idea that gaining administrator privileges through local escalation on a personal desktop is A Big Deal(TM) is silly.

r1ch 7y ago
Microsoft considers this kind of escalation a security issue and will issue patches if this is found in Windows components. If Steam is installed on a corporate network PC (game development, QA services, esports teams, etc?), regular users being able to elevate to machine admin is a big deal.
- AnIdiotOnTheNet 7y ago
  > Microsoft considers this kind of escalation a security issue and will issue patches if this is found in Windows components. Makes sense, because Windows is also used for servers. The Steam client is not. > If Steam is installed on a corporate network PC (game development, QA services, esports teams, etc?), regular users being able to elevate to machine admin is a big deal. No it isn't. This is effectively the same as being installed on some home PC. Being local admin on the workstation doesn't really give you any more ability to do damage than just a regular user account. A non-administrative process still has access to all the user's stuff, and all the network resources that user account has access to. Local admin doesn't really give you anything new.
  - deleted 7y ago
    [deleted]
    - deleted 7y ago
      [deleted]
  - lurker458 7y ago
    local admin on windows is similar to having sudo rights on linux. It can be used to access personal files and running sessions of other users on the same machine, to install malware that will affect other users, to change drivers, to block AV or GPO policies from being applied to protect them, etc.
    - delfinom 7y ago
      Local admin just makes the life of IT guys more difficult. It's why we don't give it out to your typical "worker drone" employees because they'll manage to install many flash players that want to admin escalate....
      - AnIdiotOnTheNet 7y ago
        I've found the opposite, that for the most part people just want to be able to do their job and sometimes they need administrator rights for that, and it is incredibly annoying and frictionful if they need to contact IT every time. Since workstations are almost always 1:1, we don't consider whatever advantages local admin might provide an attacker to be worth the extra friction caused by disallowing it.
0xDEFC0DE 7y ago
>The whole idea that gaining administrator privileges through local escalation on a personal desktop is A Big Deal(TM) is silly. I’ve seen steam on work computers. This isn’t limited to home desktop users by any stretch. People install steam because they don’t know it puts their work computers at risk. You could argue that they shouldn’t have games on a work PC (some companies are a bit more lax and even play together) and an easy way to convince them to not do that is if you point out that Steam makes your system less secure by design.
- AnIdiotOnTheNet 7y ago
  > People install steam because they don’t know it puts their work computers at risk. Tell me, what precisely does having administrator privileges on a workstation provide that having the user account's privileges does not? With the user account you still have access to the user's files (and they are almost certainly the only user of that workstation) and all network resources they have access to.
  - 0xDEFC0DE 7y ago
    Install persistence, stealth like clearing logs, gather more information from AD, run code that wouldn’t otherwise be possible. But no let’s just forget all of the reasons we use group policy and principles of least privileges. Imagine if your initial foothold is user with Steam installed. You just got SYSTEM for free.
    - AnIdiotOnTheNet 7y ago
      > gather more information from AD What good is the computer account for this when you already have the user account? > But no let’s just forget all of the reasons we use group policy and principles of least privileges. By that rationale, computer accounts should have far fewer privileges than the actual user account anyway, so again having local admin isn't worth much. > run code that wouldn’t otherwise be possible Namely? > Imagine if your initial foothold is user with Steam installed. You just got SYSTEM for free. And I'm struggling to see how that adds much to my problem of someone having a foothold on a user workstation already. And that's ignoring the circumstances of Steam being installed on the workstation in the first place AND the user having installed some untrustworthy game with it in the window since the game's appearance on Steam and its detection and removal. Which is also not to mention that this means the user has the ability to install software and is therefore infinitely more likely to just download some malicious installer from the nefarious portions of the internet that they can access with a web browser.
jerf 7y ago
As the degree of privilege you get on a system goes up, your ability to persist attacks increases. In the limit you end up with cases where the malware is running as a hypervisor, rendering Windows actually entirely incapable of seeing it or dealing with it. I seem to recall some countermeasures have been added but I don't recall all the details or know what the current status of that is, but I'm fairly sure that has has happened in the wild, not just a theoretical attack. So even if someone gets exec on your user files, you'd still prefer them to be limited to your user and not running at higher priv levels. Even if 90% of the damage is done with access to your personal files, it still adds more damage with higher privs. Plus this means user-level countermeasures like "run steam as a separate user" are useful; with escalation, that's not an effective defense. Also, if you've got multiple users on the computer, an attack that can't escalate privileges might ruin your day, but an attack that can escalate privileges might ruin your day and your spouse's day and anyone else in your family's day, so even in terms of "personal files" on a modern Windows system you can still be looking at more damage from an escalating attack.
- AnIdiotOnTheNet 7y ago
  Of the people trying to say this is a big deal in any way, I must say that so far you are the only one to make any reasonable points. > So even if someone gets exec on your user files, you'd still prefer them to be limited to your user and not running at higher priv levels. Even if 90% of the damage is done with access to your personal files, it still adds more damage with higher privs. This is debatable, since whatever other damage they could do is something I'm not likely to care very much about compared to all my work, the whole reason I have a computer in the first place, being held for ransom or otherwise lost to me. > Plus this means user-level countermeasures like "run steam as a separate user" are useful; with escalation, that's not an effective defense. I suppose this is true, however I don't think any competent authority will tell you that simply running a program you don't trust as another user should ever be relied upon as a sandboxing mechanism anyway. > Also, if you've got multiple users on the computer, an attack that can't escalate privileges might ruin your day, but an attack that can escalate privileges might ruin your day and your spouse's day and anyone else in your family's day, so even in terms of "personal files" on a modern Windows system you can still be looking at more damage from an escalating attack. That's a fair point.
la_barba 7y ago
I think we all realize that you don't need admin privileges to do harm. Simply having any kind of access is sufficient. But if you want to install a system wide keylogger to get access to bank/finance logins, for e.g.. admin privs help.
- AnIdiotOnTheNet 7y ago
  Eh, not as much as you'd think. I've written keyloggers. In the XP days running a keylogger under local admin ensured you'd get everything, but that stopped working around the time of Vista. So now what you have to do is launch your keylogger process in the user session context anyway. Admin access would just get you the ability to do it to more than just the initially compromised account, but in my experience workstations are 1:1 so that doesn't really get you anything.
  - la_barba 7y ago
    Hmm, don't you need SeDebugPrivilege to access the process space of another process launched by the same user account?