IM
IronMonkey Threat Research

CVE-2026-23457 HIGH

Published: 2026-04-03 | Last Modified: 2026-07-24 | Status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() sip_help_tcp() parses the SIP Content-Length header with simple_strtoul(), which returns unsigned long, but stores the result in unsigned int clen. On 64-bit systems, values exceeding UINT_MAX are silently truncated before computing the SIP message boundary. For example, Content-Length 4294967328 (2^32 + 32) is truncated to 32, causing the parser to miscalculate where the current message ends. The loop then treats trailing data in the TCP segment as a second SIP message and processes it through the SDP parser. Fix this by changing clen to unsigned long to match the return type of simple_strtoul(), and reject Content-Length values that exceed the remaining TCP payload length.

Additional Descriptions (1)

En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: netfilter: nf_conntrack_sip: corrección de la truncación u32 de Content-Length en sip_help_tcp() sip_help_tcp() analiza la cabecera SIP Content-Length con simple_strtoul(), que devuelve unsigned long, pero almacena el resultado en unsigned int clen. En sistemas de 64 bits, los valores que exceden UINT_MAX se truncan silenciosamente antes de calcular el límite del mensaje SIP. Por ejemplo, Content-Length 4294967328 (2^32 + 32) se trunca a 32, provocando que el analizador calcule erróneamente dónde termina el mensaje actual. El bucle entonces trata los datos restantes en el segmento TCP como un segundo mensaje SIP y lo procesa a través del analizador SDP. Se corrige esto cambiando clen a unsigned long para que coincida con el tipo de retorno de simple_strtoul(), y rechazando los valores de Content-Length que exceden la longitud restante de la carga útil TCP.

CVSS Metrics

Base Score: 8.6 (HIGH)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

Attack VectorNETWORK
Attack ComplexityLOW
Privileges RequiredNONE
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactLOW
Integrity ImpactLOW
Availability ImpactHIGH

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Type: Secondary

Exploitability Score: 3.9

Impact Score: 4.7

Weaknesses

Source Type Description
[email protected] Primary
en NVD-CWE-noinfo

Affected Products

Vendor Product Version Update Type
linux linux_kernel * <built-in method update of dict object at 0x7d24246c3640> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d2424535d80> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d24246070c0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d2424535dc0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d23a531d640> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d23a531fcc0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7d23af2bfc00> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d2424536800> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d23af2be300> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d24246c27c0> Operating System
linux linux_kernel 7.0 <built-in method update of dict object at 0x7d23af2be840> Operating System

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*

References

Notification
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