Subject: [ASA-201901-16] nasm: denial of service

Arch Linux Security Advisory ASA-201901-16
==========================================

Severity: Medium
Date    : 2019-01-24
CVE-ID  : CVE-2019-6290 CVE-2019-6291
Package : nasm
Type    : denial of service
Remote  : No
Link    : https://security.archlinux.org/AVG-852

Summary
=======

The package nasm before version 2.14.02-1 is vulnerable to denial of
service.

Resolution
==========

Upgrade to 2.14.02-1.

# pacman -Syu "nasm>=2.14.02-1"

The problems have been fixed upstream in version 2.14.02.

Workaround
==========

None.

Description
===========

- CVE-2019-6290 (denial of service)

An infinite recursion issue was discovered in eval.c in Netwide
Assembler (NASM) through 2.14.02. There is a stack exhaustion problem
resulting from infinite recursion in the functions expr, rexp, bexpr
and cexpr in certain scenarios involving lots of '{' characters. Remote
attackers could leverage this vulnerability to cause a denial-of-
service via a crafted asm file.

- CVE-2019-6291 (denial of service)

An issue was discovered in the function expr6 in eval.c in Netwide
Assembler (NASM) through 2.14.02. There is a stack exhaustion problem
caused by the expr6 function making recursive calls to itself in
certain scenarios involving lots of '!' or '+' or '-' characters.
Remote attackers could leverage this vulnerability to cause a denial-
of-service via a crafted asm file.

Impact
======

A local attacker is able to cause a denial of service via a specially
crafted asm file.

References
==========

https://bugzilla.nasm.us/show_bug.cgi?id=3392548
https://bugzilla.nasm.us/show_bug.cgi?id=3392549
https://security.archlinux.org/CVE-2019-6290
https://security.archlinux.org/CVE-2019-6291