Home » Posts tagged "exploit"

VirtualBox 5.2 的 0day 爆破...

Hacker News Daily 上看到「VirtualBox E1000 Guest-to-Host Escape」這篇,講 VirtualBox 5.2 的機器上 E1000 + NAT 模式的爆破... 另外在 Hacker News 上的討論也提到了很多這樣做的背景:「VirtualBox E1000 Guest-to-Host Escape | Hacker News」。

Oracle 對社群的態度 (無論是 open source community 或是 security community) 都一直是社群很不爽的事情。

這次爆破的發現人之前找到一個 VirtualBox 的 security bug (參考「SSD Advisory – VirtualBox VRDP Guest-to-Host Escape」),回報後先是回應他們在處理中,然後被發現 VirtualBox 在 5.2.18 修掉了,但是完全沒有提到安全性問題的事情。所以這次作者也懶得囉唆了,找到就 full disclosure 出來。

作者給的 workaround 有兩個,優先建議暫時先用 PCnet 系列的界面,如果不行的話,至少不要用 NAT。

作者發表後沒多久馬上就有 5.2.22 推出,不過看 changelog 應該是沒有修正這個問題?(或是修掉又沒提...)

CVE-2018-14665:setuid 複寫檔案的 security issue...

Twitter 上看到的 security issue,好久沒在這麼普及的軟體上看到這種 bug 了:

CVE - CVE-2018-14665 的說明裡面有提到 1.20.3 前的版本都有中,但沒講到從哪個版本開始,看起來是全系列...?

A flaw was found in xorg-x11-server before 1.20.3. An incorrect permission check for -modulepath and -logfile options when starting Xorg. X server allows unprivileged users with the ability to log in to the system via physical console to escalate their privileges and run arbitrary code under root privileges.

這一臉 orz...

Cisco 與 Fortinet 防火牆的 RCE 漏洞

NSA 使用這些漏洞來大量監聽企業的流量:「Leaked Exploits are Legit and Belong to NSA: Cisco, Fortinet and Snowden Docs Confirm」。

Cisco 已經確認這個安全性漏洞了,全系列包括已經停產的 Cisco PIX、上個世代的 Cisco ASA 5500 (但還有些型號還在賣),以及目前主力的 Cisco ASA 5500-X,另外還包括了安全模組系列也中獎:「Cisco Adaptive Security Appliance SNMP Remote Code Execution Vulnerability」。

  • Cisco ASA 5500 Series Adaptive Security Appliances
  • Cisco ASA 5500-X Series Next-Generation Firewalls
  • Cisco ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers
  • Cisco ASA 1000V Cloud Firewall
  • Cisco Adaptive Security Virtual Appliance (ASAv)
  • Cisco Firepower 4100 Series
  • Cisco Firepower 9300 ASA Security Module
  • Cisco Firepower Threat Defense Software
  • Cisco Firewall Services Module (FWSM)*
  • Cisco Industrial Security Appliance 3000
  • Cisco PIX Firewalls*

標星號的是目前已經沒有在維護的產品,這次只確認受到影響,但不會更新:

Cisco Firewall Service Modules and Cisco PIX Firewalls have passed the last day of software support milestone as stated in the published End of Life (EoL) documents. Further investigations into these devices will not be performed, and fixed software will not be made available.

這次 Cisco 的安全性問題是 SNMP 的洞造成的:

Administrators are advised to allow only trusted users to have SNMP access and to monitor affected systems using the snmp-server host command.

這個洞被 NSA 用來寫 exploit 植入系統:

This flaw was included inside two NSA exploits, dubbed EPICBANANA as well as JETPLOW, which is an enhanced version of EPICBANANA, but with better persistence capabilities, Cisco's Omar Santos said in a blog post.

在 NSA 洩漏出來的文件裡可以看到 ace02468bdf13579 這個特殊辨識字串,而在受感染的樣本上也找到了這個痕跡:

而且不只是 Cisco,其他幾家也中獎了,可以參考「The NSA Leak Is Real, Snowden Documents Confirm」這邊更多的資訊 @_@

CVE-2015-7547:getaddrinfo() 的 RCE (Remote Code Execution) 慘案

Google 寫了一篇關於 CVE-2015-7547 的安全性問題:「CVE-2015-7547: glibc getaddrinfo stack-based buffer overflow」。

Google 的工程師在找 OpenSSH 連到某台特定主機就會 segfault 的通靈過程中,發現問題不在 OpenSSH,而是在更底層的 glibc 導致 segfault:

Recently a Google engineer noticed that their SSH client segfaulted every time they tried to connect to a specific host. That engineer filed a ticket to investigate the behavior and after an intense investigation we discovered the issue lay in glibc and not in SSH as we were expecting.

由於等級到了 glibc 這種每台 Linux 都有裝的情況,在不經意的情況下發生 segfault,表示在刻意攻擊的情況下可能會很糟糕,所以 Google 投入了人力研究,想知道這個漏洞到底可以做到什麼程度:

Thanks to this engineer’s keen observation, we were able determine that the issue could result in remote code execution. We immediately began an in-depth analysis of the issue to determine whether it could be exploited, and possible fixes. We saw this as a challenge, and after some intense hacking sessions, we were able to craft a full working exploit!

在研究過程中 Google 發現 Red Hat 的人也在研究同樣的問題:「(CVE-2015-7547) - In send_dg, the recvfrom function is NOT always using the buffer size of a newly created buffer (CVE-2015-7547)」:

In the course of our investigation, and to our surprise, we learned that the glibc maintainers had previously been alerted of the issue via their bug tracker in July, 2015. (bug). We couldn't immediately tell whether the bug fix was underway, so we worked hard to make sure we understood the issue and then reached out to the glibc maintainers. To our delight, Florian Weimer and Carlos O’Donell of Red Hat had also been studying the bug’s impact, albeit completely independently! Due to the sensitive nature of the issue, the investigation, patch creation, and regression tests performed primarily by Florian and Carlos had continued “off-bug.”

攻擊本身需要繞過反制機制 (像是 ASLR),但仍然是可行的,Google 的人已經成功寫出 exploit code:

Remote code execution is possible, but not straightforward. It requires bypassing the security mitigations present on the system, such as ASLR. We will not release our exploit code, but a non-weaponized Proof of Concept has been made available simultaneously with this blog post.

技術細節在 Google 的文章裡也有提到,buffer 大小固定為 2048 bytes,但取得時有可能超過 2048 bytes,於是造成 buffer overflow:

glibc reserves 2048 bytes in the stack through alloca() for the DNS answer at _nss_dns_gethostbyname4_r() for hosting responses to a DNS query.

Later on, at send_dg() and send_vc(), if the response is larger than 2048 bytes, a new buffer is allocated from the heap and all the information (buffer pointer, new buffer size and response size) is updated.

另外 glibc 官方的 mailing list 上也有說明:「[PATCH] CVE-2015-7547 --- glibc getaddrinfo() stack-based buffer overflow」。

libpng 漏洞...

libpng 的安全性問題,CVE-2015-8126

Multiple buffer overflows in the (1) png_set_PLTE and (2) png_get_PLTE functions in libpng before 1.0.64, 1.1.x and 1.2.x before 1.2.54, 1.3.x and 1.4.x before 1.4.17, 1.5.x before 1.5.24, and 1.6.x before 1.6.19 allow remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a small bit-depth value in an IHDR (aka image header) chunk in a PNG image.

一堆軟體要更新啊...

Adobe 的 Typekit 推廣 HTTPS only

AdobeTypekit 宣佈之後的 embed code 預設就會是 HTTPS only:「Font loading update: All HTTPS, all the time」。

主要的原因是出自於最近發現的安全問題,攻擊者可以藉由字型處理的 security issue 攻擊,而導入 HTTPS 後可以降低這部分的風險:

We’ve made this change as a response to the recent vulnerabilities and exploits in the OpenType and TrueType font formats. A malicious attacker could use these vulnerabilities to modify a Typekit font while it is being transmitted from our servers to your browser. Serving fonts (and other resources) over HTTPS ensures that the communication channel between your browser and our servers is not compromised and fonts are delivered in a secure way.

就目前看起來,use.typekit.net 還是使用 EdgeCast 的 CDN 服務,在 HTTPS 上還是沒有 SPDY 或是 HTTP/2,對效能的影響還是要測試過才知道...

Hacking Team 購買 Flash Exploit 的信件

前情提要:「Hacking Team 被黑而洩漏出來的資料」。

在「How a Russian hacker made $45,000 selling a 0-day Flash exploit to Hacking Team」這邊提到了 Hacking Team 被黑而洩漏出來的信件,透漏了俄羅斯的人賣 Flash Exploit 給 Hacking Team 的過程。

從內容就可以看出不同的賣法,包括「首次」與「獨家」都是可以談的條件:

1) The price is US$45,000.00 for the non-exclusive sale of any special discount for the "first" deal together will be greatly appreciated :)

然後有些東西是另外加密通信的:

The two men then exchanged PGP keys, which they used to exchange a number of encrypted messages, presumably one including how Toporov would like to be paid.

然後還有 invoice:

而買了幾個建立關係後,後面還會有 discount:

Now your discount on the next buy is -5k and -10k is for a third bug.

最近應該會有不少人跳下去解讀洩漏出來的資料...

Hacking Team 被黑而洩漏出來的資料

這幾天資安領域最熱鬧的消息莫過於 Hacking Team 被黑之後洩漏出來的 400GB+ 的資料:「Hacking Team hacked, attackers claim 400GB in dumped data」、「Hacking Team hacked, attackers claim 400GB in dumped data」。

洩漏的資料可以在 GitHub 上的「hackedteam」取得,或是透過 BitTorrent 取得 (i.e. 51603bff88e0a1b3bad3962614978929c9d26955)。

烏雲上的「人手一份核武器 - Hacking Team 泄露(开源)资料导览手册」這篇寫得很完整了,現在的系統已經整合到這樣,於是要對這個人做任何事情都很容易:

也因為這次的 leak 而使得不少軟體在修正 0day exploit...

好精緻的核武...

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