¡¾Îó²îͨ¸æ¡¿OpenSSH ȨÏÞÌáÉýÎó²î (CVE-2021-41617)

Ðû²¼Ê±¼ä 2021-09-27

0x00 Îó²î¸ÅÊö

CVE     ID

CVE-2021-41617

ʱ      ¼ä

2021-09-26

Àà      ÐÍ

ȨÏÞÌáÉý

µÈ      ¼¶

¸ßΣ

Ô¶³ÌʹÓÃ


Ó°Ïì¹æÄ£

6.2 - 8.7

¹¥»÷ÖØÆ¯ºó


¿ÉÓÃÐÔ


Óû§½»»¥


ËùÐèȨÏÞ


PoC/EXP


ÔÚҰʹÓÃ

·ñ

 

0x01 Îó²îÏêÇé

image.png

OpenSSH ÊÇ SSH £¨Secure SHell£© ЭÒéµÄÃâ·Ñ¿ªÔ´ÊµÏÖ ¡£¡£¡£¡£¡£¡£¡£¡£

2021Äê9ÔÂ26ÈÕ£¬£¬£¬£¬ £¬OpenSSHÏîÄ¿Ðû²¼ÁËOpenSSH 8.8Çå¾²¸üУ¬£¬£¬£¬ £¬ÐÞ¸´ÁËOpenSSH 6.2 µ½ 8.7°æ±¾ÖÐµÄ sshd(8)ÖеÄÒ»¸öȨÏÞÌáÉýÎó²î£¨CVE-2021-41617£© ¡£¡£¡£¡£¡£¡£¡£¡£

µ±sshd(8) ÔÚÖ´ÐÐ AuthorizedKeysCommand »ò AuthorizedPrincipalsCommand ʱ£¬£¬£¬£¬ £¬Î´ÄÜ׼ȷµØ³õʼ»¯£¬£¬£¬£¬ £¬ÆäÖÐAuthorizedKeysCommandUser »ò AuthorizedPrincipalsCommandUser Ö¸Áî±»ÉèÖÃΪÒÔ·ÇrootÓû§Éí·ÝÔËÐÐ ¡£¡£¡£¡£¡£¡£¡£¡£Ïà·´£¬£¬£¬£¬ £¬ÕâЩÏÂÁ¼ÌÐø sshd(8) Æô¶¯Ê±µÄ×éµÄȨÏÞ£¬£¬£¬£¬ £¬Æ¾Ö¤ÏµÍ³ÉèÖõIJî±ð£¬£¬£¬£¬ £¬¼ÌÐøµÄ×é¿ÉÄÜ»áÈø¨Öú³ÌÐò»ñ×ÔµÃÍâµÄȨÏÞ£¬£¬£¬£¬ £¬µ¼ÖÂȨÏÞÌáÉý ¡£¡£¡£¡£¡£¡£¡£¡£

ÔÚ sshd_config(5) ÖУ¬£¬£¬£¬ £¬AuthorizedKeysCommand ºÍ AuthorizedPrincipalsCommand ¶¼Ã»Óб»Ä¬ÈÏÆôÓà ¡£¡£¡£¡£¡£¡£¡£¡£

 

Ó°Ïì¹æÄ£

OpenSSH °æ±¾6.2 - 8.7

 

0x02 ´¦Öóͷ£½¨Òé

ÏÖÔÚ´ËÎó²îÒѾ­ÐÞ¸´£¬£¬£¬£¬ £¬½¨ÒéÊÜÓ°ÏìµÄÓû§ÊµÊ±Éý¼¶¸üе½OpenSSH 8.8 ¡£¡£¡£¡£¡£¡£¡£¡£

ÏÂÔØÁ´½Ó£º

http://www.openssh.com/releasenotes.html

 

0x03 ²Î¿¼Á´½Ó

https://www.openssh.com/security.html

https://www.openssh.com/txt/release-8.8

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41617

 

0x04 ¸üа汾

°æ±¾

ÈÕÆÚ

ÐÞ¸ÄÄÚÈÝ

V1.0

2021-09-27

Ê×´ÎÐû²¼

 

0x05 Îĵµ¸½Â¼

CNVD£ºwww.cnvd.org.cn

CNNVD£ºwww.cnnvd.org.cn

CVE£ºcve.mitre.org

CVSS£ºwww.first.org

NVD£ºnvd.nist.gov

 

0x06 ¹ØÓÚ¿­·¢k8

¹Ø×¢ÒÔϹ«Öںţ¬£¬£¬£¬ £¬»ñÈ¡¸ü¶à×ÊѶ£º

image.png