flatedecode

Foxit Reader FlateDecode Heap Buffer Overflow Remote Code Execution VulnerabilityFoxit Reader FlateDecode Heap Buffer Overflow Remote Code Execution Vulnerability Release date:Updated on:Affected Systems: Foxit Reader Description: Foxit Reader is a small PDF document viewer and print program.The FlateDecode of Foxit Reader has a security vulnerability. Remo

stuff...Chpwn explains that Comex uses the CFF font overflow vulnerability to jailbreak. It is a font file vulnerability in a FlateDecode data stream. For more information about FlateDecode, see the explanation www.2cto.com:@ Chpwn has explained that @ comex uses the CFF font stack overflow to jailbreak, which is essential a font file placed in a FlateDecode str

. Font; 3. Compressed Post Script [2].The following uses a PDF file with only one sentence for analysis. Use UltraEdit to open the PDF file and select hexadecimal to edit the file to view information similar to the following. I will focus on selecting some information for introduction, use # to annotate and explain it later.% PDF-1.6 # documentation header, compliant with specification 1.6% Too many # below are many Object objects2 0 obj # Object, where 2 is the sequence number of Obj and 0 is t

required if you want to open a webpage in a PDF file. /The Filter is generally FlateDecode, that is, the zlib compression and decompression algorithm is used. For details, refer to [2]. /JBIG2Decode indicates that the PDF file is compressed using JBIG2. Although JBIG2 compression itself may have a vulnerability (CVE-2010-1297 ). However, the/JBIG2Decode keyword does not indicate whether the PDF file is suspicious. /RichMedia Flash file /Launch execut

. Static Analysis When analyzing the. PDF file, we found a suspicious FontDescriptor (font description) object internally. (The FontDescriptor object is used to describe the fonts used in the. PDF file .) The font data is encoded using FlateDecode. When we deploy it, we can see a SING table and immediately discover suspicious content. Its uniqueName (unique name) field should be a 27-character string that adopts 7-bit ASCII encoding and ends with N

Starting from example 1.5, the reference information is stored in the reference stream instead of the reference table. The reference stream improves the following advantages:More concise and compact representation of reference information.You can access the compressed objects stored in the object stream (see section 3.4.6, "Object stream"), and allow new objects to be added later.. But it also increases the difficulty of parsing data. I will analyze the PDF reference stream below:Read a sample.p

(' endobj ');}$MQR =get_magic_quotes_runtime ();Set_magic_quotes_runtime (0);foreach ($this->fontfiles as $file = $info){Font file Embedding$this->_newobj ();$this->fontfiles[$file] [' n ']= $this->n;if (defined (' Fpdf_fontpath '))$file =fpdf_fontpath. $file;$size =filesize ($file);if (! $size)$this->error (' Font file not found ');$this->_out (' $this->_out ('/filter/flatedecode ');$this->_out ('/length1 '. $info [' length1 ']);if (Isset ($info ['

;_out (' endobj ');}$MQR =get_magic_quotes_runtime ();Set_magic_quotes_runtime (0);foreach ($this->fontfiles as $file => $info){Font file Embedding$this->_newobj ();$this->fontfiles[$file] [' n ']= $this->n;if (defined (' Fpdf_fontpath '))$file =fpdf_fontpath. $file;$size =filesize ($file);if (! $size)$this->error (' Font file not found ');$this->_out (' if (substr ($file, -2) = = '. Z ')$this->_out ('/filter/flatedecode ');$this->_out ('/length1 '. $

Foxit Reader/PhantomPDF post-release Reuse Vulnerability (CVE-2016-4059)Foxit Reader/PhantomPDF post-release Reuse Vulnerability (CVE-2016-4059) Release date:Updated on:Affected Systems: Foxit ReaderFoxit Phantom PDF Description: CVE (CAN) ID: CVE-2016-4059Foxit Reader is a small PDF document viewer and print program.Foxit Reader/PhantomPDF versions earlier than 7.3.4 have the vulnerability of reuse after being released. The FlateDecode stream

= get_magic_quotes_runtime ();Set_magic_quotes_runtime (0 );Foreach ($ this-> FontFiles as $ file => $ info){// Font file embedding$ This-> _ newobj ();$ This-> FontFiles [$ file] ['n'] = $ this-> n;If (defined ('fpdf _ fontpath '))$ File = FPDF_FONTPATH. $ file;$ Size = filesize ($ file );If (! $ Size)$ This-> Error ('font file not found ');$ This-> _ out ('$ This-> _ out ('/Filter/FlateDecode ');$ This-> _ out ('/Length1'. $ info ['length1 ']);If (

/FlateDecode ');$ This-> _ out ('/Length1'. $ info ['length1 ']);If (isset ($ info ['length2'])$ This-> _ out ('/leng2'. $ info ['leng2'].'/Length3 0 ');$ This-> _ out ('> ');$ F = fopen ($ file, 'rb ');$ This-> _ putstream (fread ($ f, $ size ));Fclose ($ f );$ This-> _ out ('endobj ');}Set_magic_quotes_runtime ($ mqr );Foreach ($ this-> fonts as $ k => $ font){// Font objects$ This-> _ newobj ();$ This-> fonts [$ k] ['n'] = $ this-> n;$ This-> _ out

= filesize ($ file );If (! $ Size)$ This-> Error ('font file not found ');$ This-> _ out ('$ This-> _ out ('/Filter/FlateDecode ');$ This-> _ out ('/Length1'. $ info ['length1 ']);If (isset ($ info ['length2'])$ This-> _ out ('/leng2'. $ info ['leng2'].'/Length3 0 ');$ This-> _ out ('> ');$ F = fopen ($ file, 'RB ');$ This-> _ putstream (fread ($ f, $ size ));Fclose ($ f );$ This-> _ out ('endobj ');}Set_magic_quotes_runtime ($ mqr );Foreach ($ this-

/FlateDecode ');$ This-> _ out ('/Length1'. $ info ['length1 ']);If (isset ($ info ['length2'])$ This-> _ out ('/leng2'. $ info ['leng2'].'/Length3 0 ');$ This-> _ out ('> ');$ F = fopen ($ file, 'RB ');$ This-> _ putstream (fread ($ f, $ size ));Fclose ($ f );$ This-> _ out ('endobj ');}Set_magic_quotes_runtime ($ mqr );Foreach ($ this-> fonts as $ k => $ font){// Font objects$ This-> _ newobj ();$ This-> fonts [$ k] ['n'] = $ this-> n;$ This-> _ out

(' endobj ');}$MQR =get_magic_quotes_runtime ();Set_magic_quotes_runtime (0);foreach ($this->fontfiles as $file = $info){Font file Embedding$this->_newobj ();$this->fontfiles[$file] [' n ']= $this->n;if (defined (' Fpdf_fontpath '))$file =fpdf_fontpath. $file;$size =filesize ($file);if (! $size)$this->error (' Font file not found ');$this->_out (' $this->_out ('/filter/flatedecode ');$this->_out ('/length1 '. $info [' length1 ']);if (Isset ($info ['

->lmargin; $w = $this->w-$this->rmargin-$this->x; $wmax = ($w -2* $this->cmargin) *1000/$this->fontsize; } $NL + +; } Else $i = $ascii? 1:2; } Last Chunk if ($i!= $j) $this->cell ($l/1000* $this->fontsize, $h, substr ($s, $j, $i-$j), 0,0, "", 0, $link); } function _putfonts () { $NF = $this->n; foreach ($this->diffs as $diff) { Encodings $this->_newobj (); $this->_out (' $this->_out (' endobj '); } $MQR =get_magic_quotes_runtime (); Set_magic_quotes_runtime (0); foreach ($this->fontfiles as $fi

(' endobj ');}$MQR =get_magic_quotes_runtime ();Set_magic_quotes_runtime (0);foreach ($this->fontfiles as $file => $info){Font file Embedding$this->_newobj ();$this->fontfiles[$file] [' n ']= $this->n;if (defined (' Fpdf_fontpath '))$file =fpdf_fontpath. $file;$size =filesize ($file);if (! $size)$this->error (' Font file not found ');$this->_out (' if (substr ($file, -2) = = '. Z ')$this->_out ('/filter/flatedecode ');$this->_out ('/length1 '. $info