// For flags

CVE-2019-17042

rsyslog: heap-based overflow in contrib/pmcisconames/pmcisconames.c

Severity Score

9.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

An issue was discovered in Rsyslog v8.1908.0. contrib/pmcisconames/pmcisconames.c has a heap overflow in the parser for Cisco log messages. The parser tries to locate a log message delimiter (in this case, a space or a colon), but fails to account for strings that do not satisfy this constraint. If the string does not match, then the variable lenMsg will reach the value zero and will skip the sanity check that detects invalid log messages. The message will then be considered valid, and the parser will eat up the nonexistent colon delimiter. In doing so, it will decrement lenMsg, a signed integer, whose value was zero and now becomes minus one. The following step in the parser is to shift left the contents of the message. To do this, it will call memmove with the right pointers to the target and destination strings, but the lenMsg will now be interpreted as a huge value, causing a heap overflow.

Se detectó un problema en Rsyslog versión v8.1908.0. El archivo contrib/pmcisconames/pmcisconames.c, presenta un desbordamiento de pila en el analizador de mensajes de registro de Cisco. El analizador intenta localizar un delimitador de mensaje de registro (en este caso, un espacio o dos puntos), pero no considera las cadenas que no satisfacen esta restricción. Si la cadena no coincide, la variable lenMsg alcanzará el valor cero y omitirá la comprobación de saneamiento que detecta mensajes de registro no válidos. El mensaje se considerará válido y el analizador consumirá el delimitador de dos puntos inexistentes. Al hacerlo, disminuirá lenMsg, un entero con signo, cuyo valor era cero y ahora se convierte en menos uno. El siguiente paso en el analizador es desplazar a la izquierda el contenido del mensaje. Para hacer esto, llamará a memmove con los punteros correctos para las cadenas de destino y apuntadas, pero el lenMsg ahora será interpretado como un gran valor, causando un desbordamiento de la pila.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2019-09-30 CVE Reserved
  • 2019-10-07 CVE Published
  • 2024-08-05 CVE Updated
  • 2024-09-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-20: Improper Input Validation
  • CWE-122: Heap-based Buffer Overflow
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Rsyslog
Search vendor "Rsyslog"
Rsyslog
Search vendor "Rsyslog" for product "Rsyslog"
8.1908.0
Search vendor "Rsyslog" for product "Rsyslog" and version "8.1908.0"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
Fedora
Search vendor "Fedoraproject" for product "Fedora"
30
Search vendor "Fedoraproject" for product "Fedora" and version "30"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
Fedora
Search vendor "Fedoraproject" for product "Fedora"
31
Search vendor "Fedoraproject" for product "Fedora" and version "31"
-
Affected
Debian
Search vendor "Debian"
Debian Linux
Search vendor "Debian" for product "Debian Linux"
9.0
Search vendor "Debian" for product "Debian Linux" and version "9.0"
-
Affected
Opensuse
Search vendor "Opensuse"
Leap
Search vendor "Opensuse" for product "Leap"
15.0
Search vendor "Opensuse" for product "Leap" and version "15.0"
-
Affected
Opensuse
Search vendor "Opensuse"
Leap
Search vendor "Opensuse" for product "Leap"
15.1
Search vendor "Opensuse" for product "Leap" and version "15.1"
-
Affected