Recently our scanner identified several vulnerabilities with Apache tomcat. The latest version in Ubuntu 20.04 is tomcat9 9.0.31-1ubuntu0.1 There are several CVE's that are fixed only in higher versions  9.0.35: CVE-2020-9484 -  9.0.36: CVE-2020-11996 -  9.0.37 - Apache Tomcat 9.0.0.M1 &lt; 9.0.37 Multiple Vulnerabilities (didn't find CVE) 9.0.38 - Apache Tomcat 8.5.x &lt; 8.5.58 / 9.0.x &lt; 9.0.38 HTTP/2 Request Mix-Up (didn't find CVE) 9.0.40 - Apache Tomcat 9.x &lt; 9.0.40 Information Disclosure (didn't find CVE)  Unfortunately, I can't upgrade due Ubuntu 20.10 due to client requirements Please advice when we should expect newer version with Focal repositories. Thanks.
Today a couple of buffer overflows in NTP were announced , . It looks like updating my system to fix these issues is in order.   How can I find out if they have been fixed in the Ubuntu repositories, such that if I were to run:   sudo apt-get update sudo apt-get upgrade   then the fix would get installed and the vulnerability closed?   Edit: The selected answer specifically addresses the question of how to identify if a given CVE has been fixed or not, "Does Ubuntu generally post timely security updates?"  is certainly related but not identical
After upgrading to Ubuntu 17.10 I noticed some of my screencasting applications are not working, for example screencasting tools like SimpleScreenRecorder and vokoscreen. ()  Also I noticed features like screenshot from GIMP is not working properly, producing blank screenshots (). Shutter too is producing glitchy screenshots ().  Screen-sharing option on Skype is also not working ().  The issue occurs sometimes on later Ubuntu releases too.  Why is this happening and how do I fix this? I want to supply constant voltage to my LED's but the supply varies from 3.7V to 4.2V (Li-ion battery). I cannot use 3.3V voltage regulator as it will need at least 4.3V voltage at the input but my battery can supply only 4.2V max. so is there any other way I can supply regulated 3.3V to my LED.   RGB LED = 3.3V, 60mA Battery = 3.7V - 4.2V, 3000mA Number of LEDs = 24 The LED's are connected in parallel Proof of inequality using AM-GM inequality prove that $x^2 + y^2 + z^2 \ge xy + xz + yz$  I tried proving it the way I prove $x^2 + y^2 \ge 2xy$. But it just doesn't seem to work. I tried using AM-GM. Should I be using GM-HM or AM-HM? I really don't know what the problem is and I'd appreciate any help and a full proof explanation. Thanks. How come if $\ i\ $ not of the following form, then $12i + 5$ must be prime? I know if $\ i\ $  of the following form $\ 3x^2 + (6y-3)x - y\ $ or $\ 3x^2 + (6y-3)x + y - 1, \ \ x,y \in \mathbb{Z}^{+},i \in \mathbb Z_{\ge 0}$,  then $\ 12i + 5\ $ must be composite number, because:  $12(3x^2 + (6y-3)x + y - 1) + 5 = 36x^2 + (72y - 36)x + (12y - 7) = (6x + 12y - 7)(6x  + 1)$  How come if $\ i\ $ not of the following form $\ 3x^2 + (6y-3)x - y\ $ and $\ 3x^2 + (6y-3)x + y - 1\ $,  then $12i + 5$ must be prime? $\ x,y \in \mathbb{Z}^{+},i \in \mathbb Z_{\ge 0}$.  For example: $\ 5 = \ 3*1^2 + (6*1-3)*1 - 1\ $ ,when $\ x = y = 1\ $, as proved before,$\ 5*12+5\ $ must be composite number;  $\ 0, \ 1. \ 2.\ 3.\ 4\ $ can't of the following form $\ 3x^2 + (6y-3)x - y\ $ and $\ 3x^2 + (6y-3)x + y - 1\ $,  $\ 12*0 + 5 = 5\ $, $\ 5 $ is prime,$\ 12*1 + 5 = 17\ $, $\ 17 $ is prime, and so on, Summary table with a field that shows components of each summarized record When to use LinkedList over ArrayList in Java? I've always been one to simply use:  List&lt;String&gt; names = new ArrayList&lt;&gt;();   I use the interface as the type name for portability, so that when I ask questions such as these I can rework my code.    When should  be used over  and vice-versa? As a disclaimer, I must admit this may benefit me (I haven't checked), but probably not as significantly as most others. This issue is also something that has prevented me from answering questions by users with 1 rep in the past, especially if they are poorly fashioned. The Problem New users with a programming question find SO from various methods, such as google. They ask a question with haste, hoping for a quick answer -- which they usually receive. Many of these users have no interest in Stack Overflow itself, but are simply interested in getting the solution they require. As a result of this, they'll check the site regularly for the first day or two until a sufficient answer has been posted. Once they get what they need, they bail; without the required rep or understanding that they should up-vote and select a response as the answer. The Result A great many questions on SO are abandoned by users with no intention of ever coming back. The answer they require has been provided, but for one or more reasons they have neglected their duty of contributing back by way of awarding reputation. The Reach (Since Jeff loves Datum) Some queries on the data dump examine the reach of this 'problem'. The query I used is based on extensions of the following base query; SELECT p1.Id, p1.Score, p1.OwnerUserId, p2.OwnerUserId, p2.Score FROM posts p1  INNER JOIN posts p2 ON (p1.Id=p2.ParentId) LEFT JOIN users ON (p1.OwnerUserId=users.Id) WHERE p2.Score &gt;= 2  AND p2.Score = ( SELECT MAX(p3.Score) FROM posts p3 WHERE p3.ParentId=p1.Id ) AND users.Reputation &lt; 15 AND p1.PostTypeId = 1 AND p1.AcceptedAnswerId = 0  Result: 3,288 Questions by users with under 15 rep which have answers with 2+ up votes that have no accepted answer. Adding: AND (users.LastAccessDate-p1.LastActivityDate) &lt; 604800 // 1 week AND p1.CreationDate &lt; 1249084800 // 1249084800 is 1 week before latest dump data  to the where clause further reveals that 877 questions that have answers with 2+ up votes have no accepted answer, and the owner of the question has not returned since the week the question was asked. Modifying there where clause, and removing the left join: AND p1.OwnerUserId = 0    Reveals a staggering 3,675 questions with answers of 2+ votes by deleted users.  These are questions that were probably answered but the users who did the work can never be recognized. Building off the previous and using an even more restrictive WHERE clause WHERE p2.Score &gt;=5  Still 1,178 posts that can never have an accepted answer. How many posts are there with over 5 up votes that don't provide the correct answer? Modifying the where clause for Reputation to AND users.Reputation = 1  Still reveals 388 questions by users with 1 rep have been abandoned. Solution Similar to how bounty questions work, if a user has abandons the site (not active since x time after the question was asked) with a question that has answers with 2+ up votes, force the answer with the most up votes to be the selected answer. This will reduce the amount of questions that are unanswered, and also give users more of an incentive to answer questions by new users without extra hesitation.  Update Added more statistics for deleted users.  Please feel free to add/remove rules to make this a truly practical feature. Why is "high" pronounced "hiy" but is not spelled that way? How to draw density estimate on histogram by pgfplots? I know how to draw a density histogram using pgfplots from this answer: .  But how can I draw an estimate line on the histogram like this?    \documentclass{article} \usepackage{pgfplots} \begin{document} \pgfplotsset{     small,     every axis plot post/.style={         fill=orange!75,         draw=orange!50!black     },     trim axis left }  \begin{tikzpicture} \begin{axis}[ymin=0, title=\texttt{hist=density}] \addplot [hist=density] table [y index=0] {random.txt}; \end{axis} \end{tikzpicture} \end{document} Uncountable well ordered set in $Z^-$ theory. I want to build an uncountable well-ordered set within the theory $Z^\textbf-$. So, I take $A=\omega$ (exists by infinity axiom) and define $$W:=\{(X,R)\in\mathcal{P}(A)\times\mathcal{P}(A\times A):\langle X,R\rangle\ \text{is a well-ordered set}\}$$  With this I consider the set $T:=W/\cong$ (where $\cong$ is isomorphism relation). Note that $W$ and $T$ are sets by power set axiom. So I define for each equivalence class $[x],[y]\in T$ the order  $$ [x]\leq_T[y]\Leftrightarrow \text{type}(x, R_x)\leq \text{type}(y,R_y) $$  Here, $R_x$ means the order of $x$ that make it belongs to $[x]$.   So, $T$ is well ordered by $\leq_T$ and it is uncountable.  Question: I don't pretty sure if I can build $\leq_ T$ without replacement axiom. Another doubt is, Can I take the $R_x$ without AC? During the end credit scene of Spider-Man: Far from Home, we see that,      Nick Fury and Maria Hill are two Skrulls, Talos and (presumably) his wife.   And we also see that,      Nick Fury is in a spaceship like structure, presumably away from Earth.   So that begs the question,      How long has Talos been impersonating Nick Fury? Is it since the events of Captain Marvel or since Avengers: Endgame or sometime in between? Proof of triangle inequality NOTE: I would appreciate it if you provided a hint and not the whole solution.  BdMO 2014 Nationals:     In acute angled triangle ABC, considering a portion of side BC as diameter a    circle is drawn whose radius is 18 units and it touches AB and AC side. Similarly,    considering a portion of sides AC and AB as diameters, two other circles are    drawn whose radii are 6 and 9 units respectively. What is the radius of the incircle    of ∆ABC?   The main problem with this  problem is that the figure is incredibly messy.So I drew one circle,and tried getting information from it.I noticed that if $O$ is a centre of one of the above (semi)circles,and if $O$ is located on $AB$, then $CO$ is an angle bisector.Therefore,if we connect all the vertices with the centres,their intersection would be the incentre.Then we need to drop a perpendicular from this point to get the inradius.But that hardly helps us.I have found some similar triangles in the figure.But that does not help me at all.  I have also tried backtracking.I tried to put myself in the problem-maker's shoes and tried to imagine what I would do if I had to create a problem like this.Unfortunately,I couldn't do it..  Any insightful comment,hint will be very much  appreciated. Proving $ \binom n 0 ^2 + \binom n 1 ^2 + \dots + \binom n n ^2 = \binom { 2n} n $ without induction I have to prove that: $$ \binom n 0 ^2  + \binom n 1 ^2  + \dots + \binom n n ^2 = \binom { 2n} n $$  I don't want a complete solution, but only a hint. As mentioned in the , Ubuntu 18.04 LTS will not have a 32 bit Desktop Image Installer. But in the  it has  32bit Desktop Images.  This is little off topic, but I'm confused. How does conservation work in wormholes? My questions might seem naive as I haven't plunged into the mathematical descriptions, but wormholes are interesting even if I don't actually know them :)  First of all, is wormhole making two possible paths betwwen points (like the tunnel in most visualisations) or is it just making two points beside each other like in the game Portal? Of course, second case can be bent into a tunnel, but there would be nothing special about tunnel part and no preferred way to divide into "normal" and "tunnel" part of spacetime.  My main questions are these:   Is momentum conserved? Is kinetic energy conserved? How does potential energy work?   To elaborate... In the game Portal you can fall into floor and fly out of the wall or floor elsewhere with the same speed, but another direction (normal to the portal). So momentum is not conserved, but kinetic energy is. Is that how it would actually work? Where does the momentum go then?  And does it really allow you to increase your potential energy while retaining kinetic? It would seem fair to take away some kinetic energy if you are put in a region where you have more potential energy.  Either way is the change in energy non-continuous like in the game and discussion that's linked below? Or are there just more than one way to move through but the change in potential energy is smooth in any of those? That would mean more potential equilibrium points though...  Similar questions has been discussed , is it correct about how the falling guys gets a lot of energy (in form of a potential one) by draining it from the mouths? Space of bounded continuous functions is complete I have lecture notes with the claim $(C_b(X), \|\cdot\|_\infty)$, the space of bounded continuous functions with the sup norm is complete.  The lecturer then proved two things, (i) that $f(x) = \lim f_n (x)$ is bounded and (ii) that $\lim f_n \in \mathbb{R}$.  I don't understand why it's not enough that $f$ is bounded. I think the limit of a sequence of continuous functions is continuous and then if $f$ is bounded, it's in $C_b(X)$. So what is this $\lim f_n \in \mathbb{R}$ about? Many thanks for your help. How to get distance when acceleration is not constant? How confident is my model? Is there a way to know? Let $f(z)=\sum\limits_{n=0}^{\infty}a_n z^n$ be an analytic function in $|z|\leq R$ such that $|f(z)|\leq M$. Prove an inequality about $f$'s zero