作者 主題: sendmail 安全漏洞  (閱讀 5145 次)

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netman

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sendmail 安全漏洞
« 於: 2003-03-04 15:56 »
下面是今天收到的  RedHat Errata ,請大家趕快修正囉:
引用
Red Hat Network has determined that the following advisory is applicable to
one or more of the systems you have registered:

Complete information about this errata can be found at the following location:
     https://rhn.redhat.com/network/errata/errata_details.pxt?eid=1504

Security Advisory - RHSA-2003:073-06
------------------------------------------------------------------------------
Summary:
Updated sendmail packages fix critical security issues

Updated Sendmail packages are available to fix a vulnerability that
may allow remote attackers to gain root privileges by sending a
carefully crafted message.

These packages also fix a security bug if sendmail is configured to use smrsh.

Description:
Sendmail is a widely used Mail Transport Agent (MTA) which is included
in all Red Hat Linux distributions.

During a code audit of Sendmail by ISS, a critical vulnerability was
uncovered that affects unpatched versions of Sendmail prior to version
8.12.8.  A remote attacker can send a carefully crafted email message
which, when processed by sendmail, causes arbitrary code to be
executed as root.

We are advised that a proof-of-concept exploit is known to exist, but
is not believed to be in the wild.

Since this is a message-based vulnerability, MTAs other than Sendmail
may pass on the carefully crafted message.  This means that unpatched
versions of Sendmail inside a network could still be at risk even if
they do not accept external connections directly.

In addition, the restricted shell (SMRSH) in Sendmail  allows attackers to
bypass the intended restrictions of smrsh by inserting additional commands
after "||" sequences or "/" characters, which are not properly filtered or
verified.  A sucessful attack would allow an attacker who has a local
account on a system which has explicitly enabled smrsh to execute arbitrary
binaries as themselves by utilizing their .forward file.

All users are advised to update to these erratum packages.  For Red Hat
Linux 8.0 we have included Sendmail version 8.12.8 which is not vulnerable
to these issues.  For all other distributions we have included a backported
patch which corrects these vulnerabilities.

Red Hat would like to thank Eric Allman for his assistance with this
vulnerability.

References:
http://www.cert.org/advisories/CA-2003-07.html
http://marc.theaimsgroup.com/?l=bugtraq&m=103350914307274
------------------------------------------------------------------------------

cisco3662

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Re: sendmail 安全漏洞
« 回覆 #1 於: 2003-05-02 11:16 »
引述: "netman"
下面是今天收到的  RedHat Errata ,請大家趕快修正囉:
引用
Red Hat Network has determined that the following advisory is applicable to
one or more of the systems you have registered:

Complete information about this errata can be found at the following location:
     https://rhn.redhat.com/network/errata/errata_details.pxt?eid=1504

Security Advisory - RHSA-2003:073-06
------------------------------------------------------------------------------
Summary:
Updated sendmail packages fix critical security issues

Updated Sendmail packages are available to fix a vulnerability that
may allow remote attackers to gain root privileges by sending a
carefully crafted message.

These packages also fix a security bug if sendmail is configured to use smrsh.

Description:
Sendmail is a widely used Mail Transport Agent (MTA) which is included
in all Red Hat Linux distributions.

During a code audit of Sendmail by ISS, a critical vulnerability was
uncovered that affects unpatched versions of Sendmail prior to version
8.12.8.  A remote attacker can send a carefully crafted email message
which, when processed by sendmail, causes arbitrary code to be
executed as root.

We are advised that a proof-of-concept exploit is known to exist, but
is not believed to be in the wild.

Since this is a message-based vulnerability, MTAs other than Sendmail
may pass on the carefully crafted message.  This means that unpatched
versions of Sendmail inside a network could still be at risk even if
they do not accept external connections directly.

In addition, the restricted shell (SMRSH) in Sendmail  allows attackers to
bypass the intended restrictions of smrsh by inserting additional commands
after "||" sequences or "/" characters, which are not properly filtered or
verified.  A sucessful attack would allow an attacker who has a local
account on a system which has explicitly enabled smrsh to execute arbitrary
binaries as themselves by utilizing their .forward file.

All users are advised to update to these erratum packages.  For Red Hat
Linux 8.0 we have included Sendmail version 8.12.8 which is not vulnerable
to these issues.  For all other distributions we have included a backported
patch which corrects these vulnerabilities.

Red Hat would like to thank Eric Allman for his assistance with this
vulnerability.

References:
http://www.cert.org/advisories/CA-2003-07.html
http://marc.theaimsgroup.com/?l=bugtraq&m=103350914307274
------------------------------------------------------------------------------



請問sendmail8.11.6-15該如何patch呢??
最近mail server老是當機,還在想會不會是這個問題.......
view過下列網址
http://www.sendmail.com/security/index.shtml
該文章並沒有提到sendmail unix like的處理方式

cisco3662

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Re: sendmail 安全漏洞
« 回覆 #2 於: 2003-05-02 11:48 »
有找到這一段

To apply the patch for sendmail 8.11 perform these steps:
cd sendmail-8.11.X
patch -p0 < /PATH/TO/sendmail.8.11.6.security.cr.patch

只要作這樣的動作就好了嗎??還有別的動作要做嗎??
因為mail server運作中....有點怕怕的...想仔細確認一下 :oops:  :oops:

netman

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sendmail 安全漏洞
« 回覆 #3 於: 2003-05-02 12:48 »
千萬別急著在 working server 上做﹗
先用 backup 在實驗用機器上 restore ,等測試通過了,
且所有 procedure 及應變策略都 ready 後,
才才才輪到 working server 啦..