RAR and UnRAR: User-assisted execution of arbitrary code — GLSA 201708-05

An integer overflow in RAR and UnRAR might allow remote attackers to execute arbitrary code.

Affected Packages

app-arch/rar on all architectures
Affected versions < 5.5.0_beta4_p20170628
Unaffected versions >= 5.5.0_beta4_p20170628
app-arch/unrar on all architectures
Affected versions < 5.5.5
Unaffected versions >= 5.5.5

Background

RAR and UnRAR provide command line interfaces for compressing and decompressing RAR files.

Description

A VMSF_DELTA memory corruption was discovered in which an integer overflow can be caused in DataSize+CurChannel. The result is a negative value of the “DestPos” variable which allows writing out of bounds when setting Mem[DestPos].

Impact

A remote attacker, by enticing a user to open a specially crafted archive, could execute arbitrary code with the privileges of the process.

Workaround

There is no known workaround at this time.

Resolution

All RAR users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose
 ">=app-arch/rar-5.5.0_beta4_p20170628"
 

All UnRAR users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-arch/unrar-5.5.5"
 

References

Release Date
August 21, 2017

Latest Revision
August 21, 2017: 1

Severity
normal

Exploitable
remote

Bugzilla entries