https://www.exploit-db.com/exploits/21229
http://www.cnnvd.org.cn/web/xxk/ldxqById.tag?CNNVD=CNNVD-200202-012

/usr/bin/at是一种免费获取使用的开放源代码的软件包，用于定时执行应用程序。许多Unix、Linux操作系统都携带了这种软件包。一般情况下/usr/bin/at都设置了suidroot属性。at程序存在输入验证漏洞，可能使本地攻击者获取主机的root权限。当从命令行接收到某些特殊的时间格式进行处理时，由于错误地对同一内存区域做了两次释放动作，可能导致某些堆区数据被破坏或重写，本地攻击者可能利用这个漏洞获取root权限。执行”/usr/bin/at31337+vuln”，如果你所在系统受此问题影响，将会看到”Segmentationfault”，否则应该看到类似信息”Garbledtime”(可能带有其他信息)。

source: http://www.securityfocus.com/bid/3886/info

at is a freely available, open source scheduler package. It is included with various Unix and Linux operating systems, and maintained by public domain.

Under some circumstances, at does not correctly handle time input. A local user attempting to schedule a task via commandline execution and using a maliciously crafted time format can cause heap corruption in at. As the at program is installed setuid root in most implementations, this could result in the execution of arbitrary code with administrative privileges. 

https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/bin-sploits/21229.tar.gz

resource:
hyperlink:http://marc.info/?l=bugtraq&m;=101128661602088&w;=2
resource:
hyperlink:http://marc.info/?l=bugtraq&m;=101147632721031&w;=2
resource:
hyperlink:http://online.securityfocus.com/advisories/3833
resource:
hyperlink:http://online.securityfocus.com/advisories/3969
resource:Patch
hyperlink:http://www.debian.org/security/2002/dsa-102
resource:
hyperlink:http://www.novell.com/linux/security/advisories/2002_003_at_txt.html
resource:Patch
hyperlink:http://www.redhat.com/support/errata/RHSA-2002-015.html
resource:Exploit
hyperlink:http://www.securityfocus.com/bid/3886
resource:
hyperlink:https://exchange.xforce.ibmcloud.com/vulnerabilities/7909