Multiple buffer overflows in Gaim 0.75 allow remote attackers to cause a denial of service and possibly execute arbitrary code via (1) octal encoding in yahoo_decode that causes a null byte to be written beyond the buffer, (2) octal encoding in yahoo_decode that causes a pointer to reference memory beyond the terminating null byte, (3) a quoted printable string to the gaim_quotedp_decode MIME decoder that causes a null byte to be written beyond the buffer, and (4) quoted printable encoding in gaim_quotedp_decode that causes a pointer to reference memory beyond the terminating null byte.

Stefan Esser of e-matters found almost a dozen remotely exploitable vulnerabilities in Gaim. From the e-matters advisory :

While developing a custom add-on, an integer overflow in the handling of AIM DirectIM packets was revealed that could lead to a remote compromise of the IM client. After disclosing this bug to the vendor, they had to make a hurried release because of a change in the Yahoo connection procedure that rendered GAIM useless. Unfourtunately at the same time a closer look onto the sourcecode revealed 11 more vulnerabilities.

The 12 identified problems range from simple standard stack overflows, over heap overflows to an integer overflow that can be abused to cause a heap overflow. Due to the nature of instant messaging many of these bugs require man-in-the-middle attacks between client and server. But the underlying protocols are easy to implement and MIM attacks on ordinary TCP sessions is a fairly simple task.

In combination with the latest kernel vulnerabilities or the habit of users to work as root/administrator these bugs can result in remote root compromises.

Stefan Esser discovered several security related problems in Gaim, a multi-protocol instant messaging client. Not all of them are applicable for the version in Debian stable, but affected the version in the unstable distribution at least. The problems were grouped for the Common Vulnerabilities and Exposures as follows :

  - CAN-2004-0005     When the Yahoo Messenger handler decodes an octal value     for email notification functions two different kinds of     overflows can be triggered. When the MIME decoder     decoded a quoted printable encoded string for email     notification two other different kinds of overflows can     be triggered. These problems only affect the version in     the unstable distribution.

  - CAN-2004-0006

    When parsing the cookies within the HTTP reply header of     a Yahoo web connection a buffer overflow can happen.
    When parsing the Yahoo Login Webpage the YMSG protocol     overflows stack buffers if the web page returns     oversized values. When splitting a URL into its parts a     stack overflow can be caused. These problems only affect     the version in the unstable distribution.

  When an oversized keyname is read from a Yahoo Messenger packet a   stack overflow can be triggered. When Gaim is setup to use an HTTP   proxy for connecting to the server a malicious HTTP proxy can   exploit it. These problems affect all versions Debian ships.
  However, the connection to Yahoo doesn't work in the version in   Debian stable.

  - CAN-2004-0007

    Internally data is copied between two tokens into a     fixed size stack buffer without a size check. This only     affects the version of gaim in the unstable     distribution.

  - CAN-2004-0008

    When allocating memory for AIM/Oscar DirectIM packets an     integer overflow can happen, resulting in a heap     overflow. This only affects the version of gaim in the     unstable distribution.

ID	Name	Product	Family	Severity
37025	FreeBSD : Several remotely exploitable buffer overflows in gaim (6fd02439-5d70-11d8-80e3-0020ed76ef5a)	Nessus	FreeBSD Local Security Checks	high
15271	Debian DSA-434-1 : gaim - several vulnerabilities	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2004-0005

critical

Tenable Plugins

high

high