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Vulnerability in the parse_via() function

High
razvancrainea published GHSA-wxfg-3gwh-rhvx Mar 15, 2023

Package

opensips (OpenSIPS Core)

Affected versions

<=3.2

Patched versions

3.1.7, 3.2.4

Description

Sending a malformed Via header to OpenSIPS triggers a segmentation fault when the function calc_tag_suffix is called. A specially crafted Via header which is deemed correct by the parser, will pass uninitialized strings to the function MD5StringArray which leads to the crash. The following is a payload that demonstrates this issue:

OPTIONS sip:127.0.0.1 SIP/2.0<CRLF>
Via: SIP/2.0/\x16UD~PTo :::]<LF>
Via: SIP/2.0/UD~PToD~PTo :::]<LF>
\x16ia: SIP/2.0/UD~PTo ::trA><CRLF>
To:. <sv:>;tga\x91o5;tga=0fe

Impact

Abuse of this vulnerability leads to Denial of Service due to a crash. Since the uninitialized string points to memory location 0x0, no further exploitation appears to be possible. No special network privileges are required to perform this attack, as long as the OpenSIPS configuration makes use of functions such as sl_send_reply or sl_gen_totag that trigger the vulnerable code.

Patches

This issue has been fixed by commit ab611f7.

References

Read more about this issue in the Audit Document section 3.10.

For more information

If you have any questions or comments about this advisory:

Severity

High
7.5
/ 10

CVSS base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVE ID

CVE-2023-27598

Weaknesses

No CWEs

Credits