cbcvebase.
CVE-2018-1000140
published 2018-03-23

CVE-2018-1000140: rsyslog librelp version 1.2.14 and earlier contains a Buffer Overflow vulnerability in the checking of x509 certificates from a peer that can result in Remote…

PriorityP261critical9.8CVSS 3.0
AVNACLPRNUINSUCHIHAH
EPSS
9.66%
95.0th percentile
rsyslog librelp version 1.2.14 and earlier contains a Buffer Overflow vulnerability in the checking of x509 certificates from a peer that can result in Remote code execution. This attack appear to be exploitable a remote attacker that can connect to rsyslog and trigger a stack buffer overflow by sending a specially crafted x509 certificate.

Affected

30 ranges· showing 25
VendorProductVersion rangeFixed in
canonicalubuntu_linux
debiandebian_linux
debiandebian_linux
debianlibrelp< librelp 1.2.15-1 (bookworm)librelp 1.2.15-1 (bookworm)
redhatenterprise_linux_desktop
redhatenterprise_linux_desktop
redhatenterprise_linux_server
redhatenterprise_linux_server
redhatenterprise_linux_server_aus
redhatenterprise_linux_server_aus
redhatenterprise_linux_server_aus
redhatenterprise_linux_server_aus
redhatenterprise_linux_server_aus
redhatenterprise_linux_server_eus
redhatenterprise_linux_server_eus
redhatenterprise_linux_server_eus
redhatenterprise_linux_server_eus
redhatenterprise_linux_server_eus
redhatenterprise_linux_server_tus
redhatenterprise_linux_server_tus
redhatenterprise_linux_server_tus
redhatenterprise_linux_server_tus
redhatenterprise_linux_server_tus
redhatenterprise_linux_workstation
redhatenterprise_linux_workstation

Detection & IOCsextracted from sources · hover to see the quote

urlhttps://github.com/rsyslog/librelp/commit/2cfe657672636aa5d7d2a14cfcb0a6ab9d1f00cf
pathsrc/tcp.c
urlhttps://github.com/rsyslog/librelp/blob/532aa362f0f7a8d037505b0a27a1df452f9bac9e/src/tcp.c#L1205
  • The vulnerable function is `relpTcpChkPeerName` in `src/tcp.c` (around line 1205). Monitor or instrument this function for abnormally large X.509 certificate field inputs that could trigger a stack-based buffer overflow.
  • Detect exploitation attempts by monitoring RELP (Reliable Event Logging Protocol) connections carrying oversized or malformed X.509 certificates from remote peers.
  • Alert on librelp versions 1.2.14 and earlier running in environments where RELP services are exposed to untrusted networks, as these are vulnerable to remote code execution via crafted X.509 certificates.
  • ·Exploitation requires the attacker to be able to connect to the rsyslog RELP service. Restricting network access to RELP services significantly reduces attack surface.
  • ·After patching librelp to version 1.2.15 or later, rsyslog must be restarted for the fix to take effect.

CVSS provenance

nvdv3.09.8CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
osv9.8CRITICAL
vendor_debian9.8CRITICAL
vendor_redhat9.8CRITICAL
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