A Vulnerability in 7-Zip Could Allow for Arbitrary Code Execution

[Gordon Dry]

https://www.cisecurity.org/advisory/a-vulnerability-in-7-zip-could-allow-for-arbitrary-code-execution_2018-049/

An updated version 18.0.5 is already released.

Quote

MS-ISAC ADVISORY NUMBER:

2018-049

DATE(S) ISSUED:

05/01/2018

OVERVIEW:

A vulnerability has been discovered in 7-Zip, which could allow for arbitrary code execution. 7-Zip is a free and open-source file archiver. Successful exploitation of this vulnerability could allow for arbitrary code execution. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

THREAT INTELLIGENCE:

 

There are currently no reports of this vulnerability being exploited in the wild.

 

SYSTEMS AFFECTED:

• 7-Zip versions prior to 18.05

RISK:

Government:

• Large and medium government entities: HIGH
• Small government entities: HIGH

Businesses:

• Large and medium business entities: HIGH
• Small business entities: HIGH

Home Users:

HIGH

TECHNICAL SUMMARY:

 

A vulnerability has been discovered in 7-Zip, which could allow for arbitrary code execution. The NArchive::NRar::CHandler::Extract method in CPP/7zip/Archive/Rar/RarHandler.cpp performs decoding of archive data using a largely uninitialized state. This state together with a lack of address space layout randomization (ASLR) on the main executables (7zFM.exe, 7zG.exe, 7z.exe) can cause memory corruptions that lead to arbitrary code execution. (CVE-2018-10115)

Successful exploitation of this vulnerability could allow for arbitrary code execution. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

 

RECOMENDATIONS:

 

We recommend the following actions be taken:

• Apply appropriate updates provided by 7-Zip to vulnerable systems, immediately after appropriate testing.
• Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
• Apply the Principle of Least Privilege to all systems and services.

 

REFERENCES:

7-Zip:

https://sourceforge.net/projects/sevenzip

landave blog:

https://landave.io/2018/05/7-zip-from-uninitialized-memory-to-remote-code-execution/

CVE:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-10115

 

[cubinator]

Good thing the version of 7zip I have on my computer is not more than two years old.

[Nuke]

nobody really uses 7zip for distribution of files so its not like its going to be a common attack vector. but its nice to see security holes fixed rather than neglected.

[kerbiloid]

28 minutes ago, Nuke said:

nobody really uses 7zip for distribution of files

Uses-uses. (Not me, not often, but I've seen that a lot of times.)
Also, a self-extracting 7zip archive is a way to deliver something to... hm... an alternatively experienced user.

P.S.
Using 7zip since dino time, currently am using more and more often that despicable old zip.
Never thought I'd fall so low. Always used arj, rar, ain, uc2, 7-zip, but never zip. And now I do.

Just because of internet.
In good old times I was compressing programs, data, docs, texts, so on.
And now I save almost only jpg, mp4, installers, other already compressed stuff. 0% compression for both 7-zip and zip, but zip opens the archives faster.

[Shpaget]

17 hours ago, Gordon Dry said:

SYSTEMS AFFECTED:

• 7-Zip versions prior to 18.05

Does this mean that 18.05 (that is the latest available at the moment) is secure?

[Gordon Dry]

4 minutes ago, Shpaget said:

Does this mean that 18.05 (that is the latest available at the moment) is secure?

That's what it means.

The info was made public after 18.05 was released.

[Shpaget]

Thanks for clarification.

Updated.

[Nuke]

15 hours ago, kerbiloid said:

Uses-uses. (Not me, not often, but I've seen that a lot of times.)
Also, a self-extracting 7zip archive is a way to deliver something to... hm... an alternatively experienced user.

P.S.
Using 7zip since dino time, currently am using more and more often that despicable old zip.
Never thought I'd fall so low. Always used arj, rar, ain, uc2, 7-zip, but never zip. And now I do.

Just because of internet.
In good old times I was compressing programs, data, docs, texts, so on.
And now I save almost only jpg, mp4, installers, other already compressed stuff. 0% compression for both 7-zip and zip, but zip opens the archives faster.

i should have said nobody uses it for file distribution. i do use it for archiving files in long term storage.