Modify

#1282 closed defect (fixed)

Null pointer dereference with file transfer request from unknown contacts

Reported by: dx Owned by:
Priority: normal Milestone:
Component: Unspecified / other Version: Unspecified
Keywords: Cc:
IRC client+version: Client-independent Operating System: Other
OS version/distro:

Description (last modified by dx)

Description

Receiving a file transfer request from a contact not in the contact list results in a null pointer dereference, leading to remote DoS by malicious remote clients.

CVE-2016-10189 has been assigned for this first issue.

Additionally, due to an incomplete fix of the issue above in BitlBee 3.5, the bitlbee-libpurple variant is still affected in 3.5.

CVE-2017-5668 has been assigned for this second issue.

Impact

This results in denial of service (remote crash of the BitlBee instance). Remote code execution does not seem to be possible (fixed offset)

For BitlBee servers configured in ForkDaemon mode (default) or inetd mode, the crash is limited to one user connection, who may just reconnect.

CVSS for bitlbee 3.4.2 and lower:

  • Access Vector: Network
  • Access Complexity: Low
  • Authentication: None
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: Partial
  • Exploitability: Functional Exploit Exists
  • Remediation Level: Official Fix
  • Report Confidence: Confirmed
  • Target Distribution: High
  • CVSS v2 score: 4.1

CVSS for bitlbee-libpurple 3.5:

  • Target Distribution: Medium
  • CVSS v2 score: 3.1

Affected versions

bitlbee-libpurple 3.5 or older

bitlbee (non-libpurple builds) 3.4.2 or older

Unaffected versions

bitlbee-libpurple 3.5.1 or newer

bitlbee (non-libpurple builds) 3.5 or newer

Resolution

  • Upgrade to 3.5.1 (released 2017-01-30)
  • For 3.5 see the attached

0001-Fix-null-pointer-dereference-on-ft-attempts-3.5.patch

  • For 3.4.2, 3.4.1 and 3.4 see the attached

0001-Fix-null-pointer-dereference-on-ft-attempts-3.4.x.patch

  • For 3.2.x and 3.2.x see the attached

0001-Fix-null-pointer-dereference-on-ft-attempts-3.0.x-3.2.x.patch

Discussion

The issue from 3.4.2 and older only affects the jabber protocol, which is the only non-purple protocol which implements file transfers.

The issue that is still present in 3.5 affects any libpurple protocol that implements file transfers when used through BitlBee. It does not affect other libpurple-based clients such as pidgin.

There's no visible effect of the issue other than the crash.

References

CVE-2016-10189: Incomplete fix commit included in 3.5:

https://github.com/bitlbee/bitlbee/commit/701ab8129ba9ea64f569daedca9a8603abad740f

CVE-2017-5668: Libpurple specific bugfix commit included in 3.5.1:

https://github.com/bitlbee/bitlbee/commit/30d598ce7cd3f136ee9d7097f39fa9818a272441

Change History (6)

comment:1 Changed at 2017-01-30T18:08:02Z by dx

  • Description modified (diff)
  • Resolution set to fixed
  • Status changed from new to closed
  • Summary changed from [reserved] to Null pointer dereference with file transfer request from unknown contacts

Made public

comment:2 Changed at 2017-01-30T18:22:06Z by dx

  • Description modified (diff)

Attachment links

comment:3 Changed at 2017-01-31T15:48:16Z by dx

  • Description modified (diff)

CVE-2016-10189 and CVE-2017-5668 have been assigned for the first issue and its incomplete fix respectively.

Add Comment

Modify Ticket

Action
as closed The ticket will remain with no owner.
The resolution will be deleted. Next status will be 'reopened'.
Author


E-mail address and user name can be saved in the Preferences.

 
Note: See TracTickets for help on using tickets.